White-Paper: Quantum Dots

Introduction

Quantum dots are nanocrystals that are usually composed of semiconductor materials, such as cadmium selenide, lead sulfide, or indium arsenide. These nanocrystals are typically between 2 and 10 nanometers in size, and they have unique electronic and optical properties that make them valuable in many commercial applications.

"New frontiers in the field of nanotechnology are being revolutionized by Quantum Dot technology, with potential applications ranging from electronics to energy to biotechnology. This technology is pushing the boundaries of what is possible and is paving the way for a more innovative and sustainable future." - Chad Mirkin, Professor of Chemistry and Director of the International Institute for Nanotechnology at Northwestern University.

Real-World Examples of Quantum Dots

One of the most significant applications of quantum dots is in the production of high-quality displays for televisions, computer monitors, and mobile devices. Quantum dots can be used to enhance the color gamut of these displays, resulting in a much wider range of colors and a more lifelike picture.

Another example of quantum dots in action is in the production of medical imaging technologies. Quantum dots can be used to create contrast agents that improve the accuracy and resolution of medical images. This has the potential to improve the accuracy of diagnoses and the effectiveness of treatments.

Quantum dots are also being used in the field of energy production. Researchers are exploring ways to use quantum dots to create highly efficient solar cells that can convert more of the sun's energy into electricity.

One of the challenges in solar cell technology is that the efficiency of the cells is limited by their ability to absorb different wavelengths of light. This is because different materials are required to absorb different wavelengths of light, which can be difficult and expensive to integrate into a single solar cell. However, quantum dots offer a solution to this problem.

Quantum dots are able to absorb different wavelengths of light depending on their size, shape, and composition. By controlling these parameters, researchers can create quantum dots that can absorb a wide range of wavelengths of light, making them highly efficient at converting solar energy into electricity. Additionally, because quantum dots can be produced using low-cost materials and simple manufacturing techniques, they have the potential to reduce the cost of solar cell production.

Commercial Applications of Quantum Dots

The commercial applications of quantum dots are vast and varied. Some of the most promising applications include:

Display Technology - Quantum dots are being used to create displays with enhanced color accuracy and brightness. This technology is already being used in high-end televisions and computer monitors, and it is expected to become more widespread in the coming years.

Medical Imaging - Quantum dots are being used to create contrast agents that can improve the accuracy and resolution of medical images. This technology has the potential to revolutionize medical imaging and improve the accuracy of diagnoses.

Lighting - Quantum dots are being used to create highly efficient, long-lasting LED lighting systems. These lighting systems have the potential to reduce energy consumption and provide more sustainable lighting solutions.

Energy Production - Researchers are exploring ways to use quantum dots to create highly efficient solar cells that can convert more of the sun's energy into electricity. This technology has the potential to provide a more sustainable and renewable energy source.

Conclusion

Quantum dots are a fascinating technology that has the potential to revolutionize many industries. From display technology to medical imaging to energy production, quantum dots are already being used in a wide range of applications. As research continues, it is likely that we will see even more commercial applications of this exciting technology in the years to come.

Jason Hartlove, CEO of Nanosys, a leading developer of quantum dot technology for displays. Commented on the use and application of this technology in more detail, stating that;

"Quantum dots represent a truly disruptive technology for the display industry. They enable a huge leap forward in color performance and deliver on the promise of more lifelike and immersive visual experiences for consumers."

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MIT and University of Tokyo's Boron Nitride Research May Unlock Commercial Applications as a Carbon Substitute

The recent development of Boron Nitride by MIT and the University of Tokyo has the potential to open up new commercial applications and could potentially surpass carbon in certain areas. Here are a few possible applications:

1. Thermal Management: Boron Nitride has high thermal conductivity and can be used in heat sinks and thermal interface materials to improve the efficiency of electronic devices.

2. Lubricants: Boron Nitride has a low coefficient of friction and is an excellent lubricant. It could be used in applications where conventional lubricants fail or degrade quickly.

3. Structural materials: Boron Nitride is extremely hard and strong, making it an ideal candidate for structural materials in aerospace and defense applications.

4. Biomedical applications: Boron Nitride has low toxicity and high biocompatibility, making it suitable for use in biomedical applications such as drug delivery, tissue engineering, and implants.

5. Electrical insulators: Boron Nitride is an excellent electrical insulator and can be used in high-voltage electrical equipment and other applications where electrical insulation is required.

Overall, the development of Boron Nitride by MIT and the University of Tokyo is a significant breakthrough that could lead to a range of new commercial applications in various industries.

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Engineered nanoparticles could help store excess carbon dioxide in the ocean

The urgent need to remove excess carbon dioxide from Earth's environment could include enlisting some of our planet's smallest inhabitants, according to an international research team led by Michael Hochella of the Department of Energy's Pacific Northwest National Laboratory.

Hochella and his colleagues examined the scientific evidence for seeding the oceans with iron-rich engineered fertilizer particles near ocean plankton. The goal would be to feed phytoplankton, microscopic plants that are a key part of the ocean ecosystem, to encourage growth and carbon dioxide (CO2) uptake. The analysis article appears in the journal Nature Nanotechnology.

"The idea is to augment existing processes," said Hochella, a Laboratory fellow at Pacific Northwest National Laboratory. "Humans have fertilized the land to grow crops for centuries. We can learn to fertilize the oceans responsibly."

In nature, nutrients from the land reach oceans through rivers and blowing dust to fertilize plankton. The research team proposes moving this natural process one step further to help remove excess CO2 through the ocean. They studied evidence that suggests adding specific combinations of carefully engineered materials could effectively fertilize the oceans, encouraging phytoplankton to act as a carbon sink.

The organisms would take up carbon in large quantities. Then, as they die, they would sink deep into the ocean, taking the excess carbon with them. Scientists say this proposed fertilization would simply speed up a natural process that already safely sequesters carbon in a form that could remove it from the atmosphere for thousands of years.

"At this point, time is of the essence," said Hochella. "To combat rising temperatures, we must decrease CO2 levels on a global scale. Examining all our options, including using the oceans as a CO2 sink, gives us the best chance of cooling the planet."

Pulling insights from the literature

In their analysis, the researchers argue that engineered nanoparticles offer several attractive attributes. They could be highly controlled and specifically tuned for different ocean environments. Surface coatings could help the particles attach to plankton. Some particles also have light-absorbing properties, allowing plankton to consume and use more CO2.

The general approach could also be tuned to meet the needs of specific ocean environments. For example, one region might benefit most from iron-based particles, while silicon-based particles may be most effective elsewhere, they say.

The researchers' analysis of 123 published studies showed that numerous non-toxic metal-oxygen materials could safely enhance plankton growth. The stability, Earth abundance, and ease of creation of these materials make them viable options as plankton fertilizers, they argue.

The team also analyzed the cost of creating and distributing different particles. While the process would be substantially more expensive than adding non-engineered materials, it would also be significantly more effective.

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Researchers reveal new knowledge of microscopic creature's durability

University of Wyoming researchers have gained further insight into the biological processes that allow microscopic creatures called tardigrades to survive extreme conditions, including being completely dried out in suspended animation for years.

Thomas Boothby, an assistant professor of molecular biology, and colleagues discovered how a sugar called trehalose works with proteins to allow tardigrades to survive a severe lack of water. Their research appears in the journal Communications Biology.

Measuring less than half a millimetre long, tardigrades—also known as water bears—can survive being completely dried out; being frozen to just above absolute zero (about minus 458 degrees Fahrenheit, when all molecular motion stops); heated to more than 300 degrees Fahrenheit; irradiated several thousand times beyond what a human could withstand; and even survive the vacuum of outer space.

Tardigrades' ability to survive being dried out has puzzled scientists, as they do so in a manner that appears to differ from a number of other organisms with the ability to enter suspended animation. At one time, scientists thought tardigrades did not manufacture trehalose to survive drying up, but Boothby and his team found that they do produce the sugar—just at lower levels than other organisms.

The researchers also found that in tardigrades, trehalose works synergistically with another tardigrade-specific protein called CAHS D.

Ultimately, Boothby and other researchers hope that their discoveries can be applied to help solve societal and global health issues—in this case, water scarcity. Their work might lead to better ways of stabilizing pharmaceuticals and generating engineered crops that can cope with harsh environments.

"A long-term goal of this field is to understand better how to confer the adaptation abilities of tardigrades to organisms that do not naturally survive drying," Boothby says. "This study and its findings provide a compelling argument that to do so may require the combination of different, synergistic protectants."

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Multi-organ chip detects dangerous nanoparticles

What happens when we breathe in nanoparticles emitted by, for example, a laser printer? Could these nanoparticles damage the respiratory tract or perhaps even other organs? To answer these questions, Fraunhofer researchers are developing the "NanoCube" exposure device.

The Nanocube's integrated multi-organ chip set up in the laboratory of the Technical University of Berlin (TU Berlin) and by its spin-off organization "TissUse" detects interaction between nanoparticles and lung cells, the uptake of nanoparticles into the bloodstream and possible effects on the liver.

Having a laser printer right next to your workstation is certainly very practical. That being said, there is the risk that these machines, just like 3D printers, could emit aerosols during operation that contain, among other things, nanoparticles—particles that are between one and one hundred nanometers in size. By comparison, one hair is about 60,000 to 80,000 nanometers thick.

Nanoparticles are also produced by passing road vehicles, for example, through the abrasion of tires. As yet, however, little is known about how these particles affect the human body when they are inhaled into the lungs. Until now, the only way to study this would have been by animal testing. What's more, large sample quantities of the relevant aerosol would have to be collected at great expense.

Directly measurable biological impact

Researchers from the Fraunhofer Institute for Toxicology and Experimental Medicine ITEM and the Fraunhofer Institute for Algorithms and Scientific Computing SCAI are collaborating with TU Berlin and its spin-off organization TissUse GmbH on the "NanoINHAL" project to investigate the impact of nanoparticles on the human body.

"We are able to analyze the biological impact of the aerosols directly and easily using in vitro methods—and without animal testing," says Dr. Tanja Hansen, Group Manager at Fraunhofer ITEM.

Combining two existing technologies has made this possible: The multi-organ chip Humimic Chip3 from TU Berlin and its spin-off organization TissUse, and the P.R.I.T. ExpoCube, developed by Fraunhofer ITEM. The Humimic Chip3 is a chip the size of a standard laboratory slide measuring 76 x 26 mm. Tissue cultures miniaturized 100,000-fold can be placed on it, with nutrient solutions supplied to the tissue cultures by micropumps. In this way, for example, tissue samples of the lung and liver and their interaction with nanoparticles can be artificially recreated.

Four of these multi-organ chips fit into the P.R.I.T. ExpoCube. This is an exposure device used to study airborne substances such as aerosols in vitro. Using a sophisticated system of micropumps, heating electronics, aerosol lines and sensors, the ExpoCube is able to expose the cell samples on the multi-organ chip to various aerosols or even nanoparticles at the air-liquid interface—as in the human lung—in a controllable and reproducible manner.

The nanoparticles flow through a microduct, from which several branches lead downward to conduct the air and nanoparticles to the four multi-organ chips. "If lung cells are to be exposed at the air-liquid interface, numerous parameters come into play, such as temperature, the flow of the culture medium in the chip, and the aerosol flow. This makes experiments of this kind very complicated," Hansen explains.

The system is currently undergoing further optimization. At the end of the project, the combination of NanoCube and multi-organ chip will facilitate detailed studies of aerosols in vitro. Only then will it be possible to investigate the direct impact of the potentially harmful nanoparticles on the respiratory tract and, at the same time, possible effects on other organs, such as the liver.

Simulations help to optimize development

But how can aerosols, in particular nanoparticles, be directed towards lung cells in such a way that a specified quantity is deposited on the cell surface? This is where the expertise of Fraunhofer SCAI comes in: The researchers studied this point and similar aspects in a simulation. They had to overcome special challenges in the process: For example, the physical and numerical models required for a detailed simulation of nanoparticles are significantly more complex than for particles with larger diameters. This, in turn, causes a significant increase in computing time.

But the time and effort are worth it, because the computationally intensive simulation helps to optimize the real-life test system. Let's take an example: As mentioned above, the aerosol has to flow through a line from which several branches extend downward to direct the nanoparticles onto the multi-organ chips, with conditions at the sampling points that are as identical as possible.

The inertial forces of the nanoparticles are low, however, so the particles would be less likely to move out of the diverted flow path and onto the cell surface. Gravity alone is not sufficient in this case. The researchers resolve the issue by exploiting the phenomenon of thermophoresis.

"This relates to a force in a fluid with a temperature gradient that causes the particles to migrate to the cooler side," explains Dr. Carsten Brodbeck, Project Manager at Fraunhofer SCAI. "By allowing the aerosol to flow through the line in a heated state, while the cells are cultivated naturally at body temperature, the nanoparticles move towards the cells, which the simulation clearly shows."

The researchers also used simulations to investigate how to achieve the highest possible temperature gradient without damaging the cells and how the corresponding device should be constructed. They also examined how different flow speeds and supply line geometries would affect uptake.

The temperature distribution in the exposure device was optimized by selecting different materials, making adjustments to the geometry and modifying the cooling and heating design. "Using simulations, we can quickly and easily change the boundary conditions and understand the effects of these changes. We can also see things that would remain hidden in experiments," explains Brodbeck.

The basic technological problems have been solved. Now, the initial prototype of the NanoCube exposure device, including a multi-organ chip, is expected to be ready in the fall, after which the first experiments with the system will be carried out.

For now, the researchers at Fraunhofer are using reference particles instead of aerosols from printers, for example, nanoparticles from zinc oxide or what is known as "carbon black", i.e. the black pigment in printing ink. In future practical applications, the measuring system is to be set up wherever the nanoparticles are produced, for example, next to a laser printer.

Innovative test system for toxic effects

The NanoINHAL project will see the creation of an innovative test system that can be used to investigate the toxic effects of airborne nanoparticles on cells in the respiratory tract and lungs, as well as on downstream organs such as the liver.

Due to the combination of two organ systems in a microphysiological system, it will also be possible to study the uptake and distribution of nanoparticles in the organism. In the future, the test system will provide data on the long-term effects of inhaled nanoparticles as well as their biokinetics. This will play a major role in assessing the potential health hazard posed by such particles.

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Exploring bioresponsive polymers for nanomedicine

Dr. Sabina Quader, senior research scientist of the Innovation Center of NanoMedicine, together with Dr. Joachim van-Guyse, assistant professor at Leiden University, has published a review article titled "Bioresponsive Polymers for Nanomedicine-Expectations and Reality!" in the journal Polymers.

Bioresponsive polymers or polymers with bioactive moieties have attracted significant attention in the field of nanomedicine because their interaction with biology enables targeted delivery and controlled release of therapeutic agents. In addition, the recent expansion of insight into complex biology and the diversification of the design and synthesis of functional polymers continue to drive innovation in nanomedicine.

Bioresponsive polymers in nanomedicine have been widely perceived to selectively activate the therapeutic function of nanomedicine at diseased or pathological sites, while sparing their healthy counterparts. This idea can be described as an advanced version of Paul Ehrlich's magic bullet concept.

From that perspective, the inherent anomalies or malfunction of the pathological sites are generally targeted to allow the selective activation or sensory function of nanomedicine. Nonetheless, while the primary goals and expectations in developing bioresponsive polymers are to elicit exclusive selectivity of therapeutic action at diseased sites, this remains difficult to achieve in practice.

Numerous research efforts have been undertaken, and are ongoing, to tackle this fine-tuning. This review summarizes key findings of biological relevance that are often used in the design of bioresponsive polymers to provide a foundation for discussion and to identify gaps between expectations and current reality.

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Simple technique ushers in long-sought class of semiconductors

Breakthroughs in modern microelectronics depend on understanding and manipulating the movement of electrons in metal. Reducing the thickness of metal sheets to the order of nanometers can enable exquisite control over how the metal's electrons move. By doing so, one can impart properties that aren't seen in bulk metals, such as ultrafast conduction of electricity. Now, researchers from Osaka University and collaborating partners have synthesized a novel class of nanostructured superlattices. This study enables an unusually high degree of control over the movement of electrons within metal semiconductors, which promises to enhance the functionality of everyday technologies.

Precisely tuning the architecture of metal nanosheets, and thus facilitating advanced microelectronic functionalities, remains an ongoing line of work worldwide. In fact, several Nobel prizes have been awarded on this topic. Researchers conventionally synthesize nanostructured superlattices—regularly alternating layers of metals, sandwiched together—from materials of the same dimension; for example, sandwiched 2D sheets. A key aspect of the present researchers' work is its facile fabrication of hetero-dimensional superlattices; for example, 1D nanoparticle chains sandwiched within 2D nanosheets.

"Nanoscale hetero-dimensional superlattices are typically challenging to prepare, but can exhibit valuable physical properties, such as anisotropic electrical conductivity," explains Yung-Chang Lin, senior author. "We developed a versatile means of preparing such structures, and in so doing we will inspire synthesis of a wide range of custom superstructures."

The researchers used chemical vapor deposition—a common nanofabrication technique in industry—to prepare vanadium-based superlattices. These magnetic semiconductors exhibit what is known as an anisotropic anomalous Hall effect (AHE): meaning directionally focused charge accumulation under in-plane magnetic field conditions (in which the conventional Hall effect isn't observed). Usually, the AHE is observed only at ultra-low temperatures. In the present research, the AHE was observed at room temperature and higher, up to around at least the boiling point of water. Generation of the AHE at practical temperatures will facilitate its use in everyday technologies.

"A key promise of nanotechnology is its provision of functionalities that you can't get from bulk materials," states Lin. "Our demonstration of an unconventional anomalous Hall effect at room temperature and above opens up a wealth of possibilities for future semiconductor technology, all accessible by conventional nanofabrication processes."

The present work will help improve the density of data storage, the efficiency of lighting, and the speed of electronic devices. By precisely controlling the nanoscale architecture of metals that are commonly used in industry, researchers will fabricate uniquely versatile technology that surpasses the functionality of natural materials.

The article, "Heterodimensional superlattice with room-temperature anomalous Hall effect," was published in Nature.

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Nanoparticles increase light scattering, boost solar cell performance

As demand for solar energy rises around the world, scientists are working to improve the performance of solar devices—important if the technology is to compete with traditional fuels. But researchers face theoretical limits on how efficient they can make solar cells.

One method for pushing efficiency beyond those limits involves adding up-conversion nanoparticles to the materials used in the solar devices. Up-conversion materials allow solar cells to harvest energy from a wider spectrum of light than normally possible. A team of scientists testing this approach found the nanoparticles boosted efficiency, but not for the reason they expected. Their research may suggest a new path forward for developing more efficient solar devices.

"Some researchers in the literature have hypothesized and showed results that up-conversion nanoparticles provide a boost in performance," said Shashank Priya, associate vice president for research and professor of materials science and engineering at Penn State. "But this research shows that it doesn't matter if you put in up-conversion nanoparticles or any other nanoparticles—they will show the boosted efficiency because of the enhance light scattering."

Adding nanoparticles is like adding millions of small mirrors inside a solar cell, the scientists said. Light traveling through the device hits the nanoparticles and scatters, potentially hitting other nanoparticles and reflecting many times within the device and providing a noticeable photocurrent enhancement.

The scientists said this light scattering process and not up-conversion led to boosted efficiency in solar devices they created.

"It doesn't matter what nanoparticles you put in, as long as they are nanosized with specific scattering properties it always leads to an increase in efficiency by a few percentage points," Kai Wang said, assistant research professor in Department of Materials Science and Engineering, and co-author of the study. "I think our research provides a nice explanation on why this type of composite light absorbing structure is interesting for the solar community."

Up-conversion nanoparticles work by absorbing infrared light and emitting visible light that solar cell can absorb and convert into additional power. Almost half of the energy from the sun reaches the Earth as infrared light, but most solar cells are unable to harvest it. Scientists have proposed that tapping into this could push solar cell efficiency past its theoretical ceiling, the Shockley-Queisser (SQ) limit, which is around 30% for single-junction solar cells powered by sunlight.

Previous studies have shown a 1% to 2% boost in efficiency using up-conversion nanoparticles. But the team found these materials provided only a very small boost in perovskite solar devices they created, the scientists said.

"We were focused initially on up-converting infrared light to the visible spectrum for absorption and energy conversion by perovskite, but the data from our Penn State colleagues indicated this was not a significant process," said Jim Piper, co-author and emeritus professor at Macquarie University, Australia. "Subsequently we provided undoped nanocrystals that do not give optical up-conversion and they were just as effective in enhancing the energy conversion efficiency."

The team performed theoretical calculations and found the boost in efficiency instead resulted from the nanoparticles' ability to improve light scattering.

"We started to basically play around with nanoparticle distribution in the model, and we started to see that as you distribute the particles far away from each other, you start to see some enhanced scattering," said Thomas Brown, associate professor at the University of Rome. "Then we had this breakthrough."

Adding the nanoparticles boosted the efficiency of perovskite solar cells by 1% in the study, the scientists reported in the journal ACS Energy Letters. The scientists said changing the shape, size and distribution of nanoparticles within these devices could yield higher efficiencies.

"So some optimum shape, distribution or size can actually lead to even more photocurrent enchantment," Priya said. "That could be the future research direction based on ideas from this research."

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A new look at disordered carbon

When carbon atoms stack into a perfectly repeating three-dimensional crystal, they can form precious diamonds. Arranged another way, in repetitive flat sheets, carbon makes the shiny gray graphite found in pencils. But there are other forms of carbon that are less well understood. Amorphous carbon—usually a sooty black material—has no repetitive molecular structure, making it challenging to study.

Now, researchers at the University of Chicago's Pritzker School of Molecular Engineering (PME) have utilized a new framework for understanding the electronic properties of amorphous carbon. Their findings let scientists better predict how the material conducts electricity and absorbs light, and were published in Proceedings of the National Academy of Sciences.

"We need to understand how disordered carbon works at a molecular level to be able to engineer this material for applications like solar energy conversion," said Giulia Galli, the Liew Family Professor of Molecular Engineering and Professor of Chemistry at the University of Chicago. Galli also holds a senior scientist appointment at Argonne National Laboratory, where she is the director of the MICCoM center.

For decades, scientists have modeled the way the atoms move in amorphous carbon using the laws of classical mechanics—the set of equations that describe, for example, how a car accelerates or how a ball falls through the air. For some heavy atoms of the periodic table, these classical equations are a good approximation to accurately capture many of the materials' properties. But for many forms of carbon, and amorphous carbons in particular, the team led by Galli has found that using these classical equations to describe the movement of atoms falls short.

"Amorphous carbon has many properties that make it valuable for a number of applications, however modeling and simulating its properties at the fundamental level is challenging," said postdoctoral research scholar Arpan Kundu, Ph.D., the first author of the paper.

Galli has spent the last thirty years developing and applying quantum mechanical methods to model and simulate the properties of molecules and solids. She originally investigated amorphous carbon at the very beginning of her career, and she has recently returned to the challenge with new insight.

Galli, Kundu and undergraduate physics researcher Yunxiang (Tony) Song carried out new simulations of the electronic properties of amorphous carbon, this time integrating quantum principles to describe the movements of both the electrons and nuclei of carbon atoms. They found that using quantum mechanics for both—rather than classical mechanics for the nuclei—is critical to accurately predict the properties of amorphous carbon.

For instance, using their refined, quantum mechanical models, the PME team predicted a higher electrical conductivity than would have been otherwise expected.

The findings reported in the PNAS article are useful not only for understanding amorphous carbon, but other similar amorphous solids as well, the researchers said. But they also pointed out that much more work remains to be done—disordered carbon materials can exhibit radically different properties depending on their density, which in turn depends on the method used to prepare the material.

"When something is arranged in a crystal, you know exactly what its structure is, but once it is disordered, it can be disordered in many possible ways," said Kundu.

The team plans to continue studying amorphous carbon and its potential applications.

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Nanoparticle 'backpacks' restore damaged stem cells

Within a newborn's umbilical cord lie potentially life-saving stem cells that can be used to fight diseases like lymphoma and leukemia. That is why many new parents elect to store ("bank") their infant's stem cell-rich umbilical cord blood. But in the 6–15% of pregnancies affected by gestational diabetes, parents lack this option because the condition damages the stem cells and renders them useless.

Now, in a study forthcoming in Communications Biology, bioengineers at the University of Notre Dame have shown that a new strategy can restore the damaged stem cells and enable them to grow new tissues again.

At the heart of this new approach are specially engineered nanoparticles. At just 150 nanometers in diameter—about a quarter of the size of a red blood cell—each spherical nanoparticle is able to store medicine and deliver it just to the stem cells themselves by attaching directly onto the stem cells' surface. Due to their special formulation or "tuning," the particles release the medicine slowly, making it highly effective even at very low doses.

Donny Hanjaya-Putra, an assistant professor of aerospace and mechanical engineering in the bioengineering graduate program at Notre Dame who directs the lab where the study was conducted, described the process using an analogy. "Each stem cell is like a soldier. It is smart and effective; it knows where to go and what to do. But the 'soldiers' we are working with are injured and weak. By providing them with this nanoparticle 'backpack,' we are giving them what they need to work effectively again."

The main test for the new "backpack"-equipped stem cells was whether or not they could form new tissues. Hanjaya-Putra and his team tested damaged cells without "backpacks" and observed that they moved slowly and formed imperfect tissues. But when Hanjaya-Putra and his team applied "backpacks," previously damaged stem cells began forming new blood vessels, both when inserted in synthetic polymers and when implanted under the skin of lab mice, two environments meant to simulate the conditions of the human body.

Although it may be years before this new technique reaches actual health care settings, Hanjaya-Putra explained that it has the clearest path of any method developed so far. "Methods that involve injecting the medicine directly into the bloodstream come with many unwanted risks and side effects," Hanjaya-Putra said. In addition, new methods like gene editing face a long journey to Food and Drug Administration (FDA) approval. But Hanjaya-Putra's technique used only methods and materials already approved for clinical settings by the FDA.

Hanjaya-Putra attributed the study's success to a highly interdisciplinary group of researchers. "This was a collaboration between chemical engineering, mechanical engineering, biology and medicine—and I always find that the best science happens at the intersection of several different fields."

The study's lead author was former Notre Dame postdoctoral student Loan Bui, now a faculty member at the University of Dayton in Ohio; stem cell biologist Laura S. Haneline and former postdoctoral fellow Shanique Edwards from the Indiana University School of Medicine; Notre Dame Bioengineering doctoral students Eva Hall and Laura Alderfer; Notre Dame undergraduates Pietro Sainaghi, Kellen Round and 2021 valedictorian Madeline Owen; Prakash Nallathamby, research assistant professor, aerospace and mechanical engineering; and Siyuan Zhang from the University of Texas Southwestern Medical Center.

The researchers hope their approach will be used to restore cells damaged by other types of pregnancy complications, such as preeclampsia. "Instead of discarding the stem cells," Hanjaya-Putra said, "in the future we hope clinicians will be able to rejuvenate them and use them to regenerate the body. For example, a baby born prematurely due to preeclampsia may have to stay in the NICU with an imperfectly formed lung. We hope our technology can improve this child's developmental outcomes."

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Researchers build longest highly-conductive molecular nanowire

As our devices get smaller and smaller, the use of molecules as the main components in electronic circuitry is becoming ever more critical. Over the past 10 years, researchers have been trying to use single molecules as conducting wires because of their small scale, distinct electronic characteristics, and high tunability. But in most molecular wires, as the length of the wire increases, the efficiency by which electrons are transmitted across the wire decreases exponentially. This limitation has made it especially challenging to build a long molecular wire—one that is much longer than a nanometer—that actually conducts electricity well.

Columbia researchers announced today that they have built a nanowire that is 2.6 nanometers long, shows an unusual increase in conductance as the wire length increases, and has quasi-metallic properties. Its excellent conductivity holds great promise for the field of molecular electronics, enabling electronic devices to become even tinier. The study is published today in Nature Chemistry.

Molecular wire designs

The team of researchers from Columbia Engineering and Columbia's department of chemistry, together with theorists from Germany and synthetic chemists in China, explored molecular wire designs that would support unpaired electrons on either end, as such wires would form one-dimensional analogs to topological insulators (TI) that are highly conducting through their edges but insulating in the center.

While the simplest 1D TI is made of just carbon atoms where the terminal carbons support the radical states—unpaired electrons, these molecules are generally very unstable. Carbon does not like to have unpaired electrons. Replacing the terminal carbons, where the radicals are, with nitrogen increases the molecules' stability. "This makes 1D TIs made with carbon chains but terminated with nitrogen much more stable and we can work with these at room temperature under ambient conditions," said the team's co-leader Latha Venkataraman, Lawrence Gussman Professor of Applied Physics and professor of chemistry.

Breaking the exponential-decay rule

Through a combination of chemical design and experiments, the group created a series of one-dimensional TIs and successfully broke the exponential-decay rule, a formula for the process of a quantity decreasing at a rate proportional to its current value. Using the two radical-edge states, the researchers generated a highly conducting pathway through the molecules and achieved a "reversed conductance decay," i.e. a system that shows an increasing conductance with increasing wire length.

"What's really exciting is that our wire had a conductance at the same scale as that of a gold metal-metal point contacts, suggesting that the molecule itself shows quasi-metallic properties," Venkataraman said. "This work demonstrates that organic molecules can behave like metals at the single-molecule level in contrast to what had been done in the past where they were primarily weakly conducting."

The researchers designed and synthesized a bis(triarylamines) molecular series, which exhibited properties of a one-dimensional TI by chemical oxidation. They made conductance measurements of single-molecule junctions where molecules were connected to both the source and drain electrodes. Through the measurements, the team showed that the longer molecules had a higher conductance, which worked until the wire was longer than 2.5 nanometers, the diameter of a strand of human DNA.

Laying the groundwork for more technological advancements in molecular electronics

"The Venkataraman lab is always seeking to understand the interplay of physics, chemistry, and engineering of single-molecule electronic devices," added Liang Li, a Ph.D. student in the lab, and a co-first author of the paper. "So creating these particular wires will lay the groundwork for major scientific advances in understanding transport through these novel systems. We're very excited about our findings because they shed light not only on fundamental physics, but also on potential applications in the future."

The group is currently developing new designs to build molecular wires that are even longer and still highly conductive.

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Magnetic nanoparticles can release anti-cancer microRNA on command

Researchers are pursuing ever-more sophisticated treatments to tackle lung cancer. Traditional chemotherapy can have serious side-effects throughout the body, so many new treatments are highly targeted. These methods allow controlled release directly at the tumor using selective agents that are less likely to produce off-target effects.

An article published in Biomedical Engineering Advances presents such a strategy. Daniel Hayes and colleagues at Pennsylvania State University in the United States created magnetic nanoparticles that can be triggered to release a therapeutic payload when stimulated using a magnetic field.

The technique should allow a doctor to administer the nanoparticles intravenously and then expose the tumor to an alternating magnetic field radiofrequency (AMF-RF) from outside the body. This will trigger the nanoparticles flowing through the area to heat up slightly and release their therapeutic payload precisely where it is needed.

The payload in question is a short strand of RNA known as a microRNA. In this case, the researchers connected the nanoparticles to a synthetic version of a microRNA called miR-148b, which has been shown to have tumor suppressing activity. Using a heat-sensitive chemical bond called a Diels-Alder cycloadduct, they joined the particles and microRNA, so that the bond would disintegrate and release the microRNA when heated using AMF-RF.

Upon testing their nanoparticles in lung cancer cells, the research team found that the particles successfully entered the cells and released their microRNA payload when exposed to AMF-RF. One day later, the researchers performed tests to see if the treated cancer cells had died.

They found that a significant number of cells had died in the group that received the nanoparticle/ AMF-RF treatment compared with groups that received no treatment, nanoparticles with no payload, or fully loaded nanoparticles but no AMF-RF. The results demonstrate that the technique has significant promise, and could pave the way for more advanced studies in animals.

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Generating high-resolution self-packaged liquid metal nanopatterns

In a new report now published in Matter, Licong An, and a team of scientists in materials engineering, industrial engineering, and the nanotechnology center at Purdue University, U.S., and Wuhan University, China, described an advanced laser lithography method. The technique facilitated the formation of electronically self-protective liquid metal patterns with feature sizes in the sub-microscale, to form one of the highest resolution metal surface patterns to date. The unique structure and robust patterns offered electrical functionality in spite of external damage. Such high-resolution, electrical, self-protective materials are suited for next-generation nano applications.

Introducing a new method: Pulsed laser lithography (PLL)

The field of high-density electronics is of great significance in materials engineering, and is suited to form high-density patterns for integrated electronics in harsh environments. Materials and industrial scientists have used room-temperature gallium indium (EGaIn) to develop high-density patterns due to their distinct properties including high fluidity, high electrical conductivity and high deformability. Research efforts to develop high-resolution liquid metal patterns are based on lithography patterning, among a diverse range of methods, with broad appeal in electronic applications across liquid metal batteries, microfluidics and energy harvesting devices.

In this work, primary author and research associate Licong An, who is presently at the materials engineering department at Purdue University, described the method as a "practical and scalable technique to fabricate self-packaged, high-resolution liquid metal patterns." The team intend to "practically integrate electric chips for use in harsh environments." The scientists primarily introduced the pulsed laser lithography method in this work to develop 3D liquid metal patterns with sub-micron level resolution, protected via a mechanically stable oxide package shell. Licong An highlighted the significance of this approach: "For the first time, the one-step lithography method can be directly used to pattern liquid metal," he said.

He further defined the practical implications of the method "due to the high surface tension and flowing patterns, when compared to traditional lithography patterning. This is the first time that a lithography method is used to directly pattern liquid metals." The work described here is therefore "a first effort to introduce advanced laser lithography as a one-step process to directly generate highly efficient liquid metal patterns," he said.

The experiments: Liquid metal nanoparticle (LMNP) development

The research team summarized the method of developing high-resolution liquid metal patterns in four steps. At first, they sprayed a liquid metal nanoparticle (LMNP) onto a substrate to form an LMNP thin film. Then focused the pulsed laser beam on the thin film surface, where the incidence beam scattered due to its surface nanostructure, followed by ablation of the LMNPs and substrate where the peak energy intensity reached an ablation threshold. The laser-induced shock acted as a squeeze to generate pressure on the liquid metal particles and the team used laser energy as the main parameter to control the formation of high-resolution patterns. The team regulated the ultrafast heating and cooling rate by laser, to generate a 3D uniform oxide layer on the top surface of the 3D architecture, with boosted mechanical stability, for high stability in the face of exterior damage.

Licong An emphasized this work as "one of the highest-resolution liquid metal patterns to date," and said, "High-resolution liquid metal patterns maintained feature sizes as small as 0.5 µm, with 0.5 µm line spacing to form one of the highest resolution liquid metal patterns to date at the sub-micron scale."

The synthesis of liquid metal nanoparticles (LMNPs)

The research team developed the liquid metal nanoparticles, according to previous reports, by ultrasonically dispersing bulk EGaIn alloy in ethanol, to form LMNPs via molecular self-assembly, with an average diameter of about 200 nm. A thin oxide layer also typically formed rapidly during the sonicating process to hold the metal particles to spherical shapes. An et al. spray-coated the as-prepared LMNPs onto a silicon-based substrate to form a thin-film of nanoparticles and kept the thin-film nonconductive, while using a fiber laser source to produce the nanopatterns. Licong An highlighted the mechanism of the advanced laser lithography technique, "the method could induce a high laser pressure, to act as a squeeze shock to generate pressure on the liquid metal particles." He continued, "when the squeeze goes by, the 200 nm particles are extruded to a 20 nm robust oxide shell, which acts as a robust package to protect the liquid metal patterns underneath from being damaged."

Materials characterization and a breakthrough

The scientists confirmed the formation of laser-induced periodic liquid metal patterns via energy-dispersive X-ray spectroscopy methods and elemental mappings to show the presence of silicon, gallium and oxide, with liquid metal imprinted on the underlying substrate. The breakthrough laser technique also broke the laser optical limit. Licong An said, "Everyone knows that there is a direct correlation between the liquid metal pattern resolution and processing tool size, our breakthrough laser lithography broke this common knowledge, to generate patterns with sub-micron resolution for the first time." 

He believes that "the patterns could reach a much higher calibration if a laser with a smaller wavelength is used." The team also simulated the formation of nanopatterns and emphasized the one-step process of direct liquid metal pattern deposition; another significant feature of the study. They combined a range of experimental methods to characterize the proprietary elemental composition of the oxide package shell covering the liquid metal nanopatterns with boosted mechanical properties—compared to pre-existing conventional methods of liquid-metal pattern generation.

Outlook: Progress and potential

In this way, Licong An and colleagues developed electronically self-protective, high-resolution liquid metal patterns via a pulsed laser lithography (PLL) method to create one of the highest resolution liquid metal patterns to date. The team envision applications of the new material in next-generation nanoscale practices, with high integration densities, suited for demanding applications. The research team comprised of key collaborations between the primary author and Research Fellow Licong An, and interdisciplinary colleagues, including Professor Gary J. Cheng, a Fellow of the American Association for the Advancement of Science.

Protein nanoparticle vaccine shows potential for broader, safe SARS-CoV-2 vaccines

A nanoparticle vaccine that combines two proteins that induce immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that has caused the global pandemic, has the potential to be developed into broader and safe SARS-CoV-2 vaccines, according to researchers in the Institute for Biomedical Sciences at Georgia State University.

The SARS-CoV-2 pandemic has caused more than six million deaths since 2019 and is a public health burden worldwide. The virus is rapidly evolving, characterized by the emergence of several significant variants.

To combat the virus, the spike protein (S) is the preferred target antigen for vaccine development based on its essential function and abundant neutralizing epitopes. However, current vaccines are limited in protecting against different variants.

This study, conducted in mice, investigates the immune responses induced by two proteins, the spike protein and its relatively conserved stem subunit (S2) of the spike protein. The results, published in the journal Small, found that the assembly of the two proteins into double-layered protein nanoparticles improves the immunogenicity of the proteins.

"The entire S protein has been used as the major antigen in vaccines against this ongoing pandemic," said Dr. Baozhong Wang, senior author of the study and Distinguished University Professor in the Institute for Biomedical Sciences at Georgia State University. "However, as the number of infections continues to rise, more and more variants have appeared and supplanted the ancestral virus. For this reason, the efficacy and protection of current vaccines are under constant threat and need continuous improvement.

"In contrast, the stem is more conserved and has fewer mutations across lineages. In addition, the stem could induce effective antibody neutralization and vigorous antibody-dependent cellular cytotoxicity (ADCC) activity against multiple variants of S protein. This work shows that the stabilized stem subunit could be a potential antigen for a SARS-CoV-2 universal vaccine against unpredictable variants."

The study found immunization with the stem induced balanced Immunoglobulin G (IgG) antibodies with potent and broad ADCC activity, a type of immune reaction in which infected cells are coated with antibodies that then recruit certain types of white blood cells to kill the infected cells. In addition, the double-layered protein nanoparticles constructed from the stem and the full-length spike protein induced more robust ADCC and neutralizing antibodies than the stem and spike protein, respectively.

The researchers also discovered nanoparticles produce more potent and balanced serum IgG antibodies than the corresponding soluble protein mixture, and the immune responses are sustained for at least four months after the immunization. With a more balanced IgG isotype antibody induced by the stem, long-lasting immune responses, and excellent safety profiles, the double-layered protein nanoparticles have the potential to be developed into broader SARS-CoV-2 vaccines, the study reports.

"The stabilized, conserved S2 stem subunit demonstrated its potential as a universal SARS-CoV-2 vaccine candidate against unpredictable variants," said Dr. Yao Ma, first author of the study and a postdoctoral research fellow in the Institute for Biomedical Sciences at Georgia State University. "Our double-layered protein nanoparticles incorporating the full-length spike protein and the S2 stem induced robust and long-term immune responses and exhibited a safety profile in our primary studies, providing an option for current SARS-CoV-2 vaccine development."

"The pandemic is far from over, and new variants continue to emerge and pose a massive threat to human health. Therefore, the updating of vaccines needs to keep pace with the times to avoid another pandemic with an unpredictable new variant."

Co-authors of the study include Yao Ma (first author), Ye Wang, Chunhong Dong, Gilbert X. Gonzalez, Wandi Zhu, Joo Kim, Lai Wei, Sang-Moo Kang, and Baozhong Wang (senior author) of the Institute for Biomedical Sciences at Georgia State University.

Making chemical separation more eco-friendly with nanotechnology

Chemical separation processes are essential in the manufacturing of many products from gasoline to whiskey. Such processes are energetically costly, accounting for approximately 10–15 percent of global energy consumption. In particular, the use of so-called "thermal separation processes," such as distillation for separating petroleum-based hydrocarbons, is deeply ingrained in the chemical industry and has a very large associated energy footprint. Membrane-based separation processes have the potential to reduce such energy consumption significantly.

Membrane filtration processes that separate contaminants from the air we breathe and the water we drink have become commonplace. However, membrane technologies for separating hydrocarbon and other organic materials are far less developed.

Penn Engineers are developing new membranes for energy-efficient organic separations by rethinking their physical structure on the nanoscale.

Nanofiltration using self-assembling membranes has been a major research area for Chinedum Osuji, Eduardo D. Glandt Presidential Professor in the Department of Chemical and Biomolecular Engineering, and his lab. The performance of these membranes was highlighted in a previous study describing how the structure of the membrane itself helped to minimize the limiting tradeoff between selectivity and permeability that is encountered in traditional nanofiltration membranes. This technology was also included in last year's Y-Prize competition, and the winners have advanced a case for its use to produce non-alcoholic beer and wine in a startup called LiberTech.

Now, Osuji's latest study adapts the membrane for filtration in organic solutions such as ethanol and isopropyl alcohol, and its self-assembling molecules make it more efficient than traditional organic-solvent nanofiltration (OSN).

The study, published in Science Advances, describes how the uniform pores of this membrane, can be fine-tuned by changing the size or concentration of the self-assembling molecules that ultimately form the material. This tunability now opens doors for the use of this membrane technology in solving more diverse real-world organic filtration problems. Researchers in the Osuji lab, including first author and former postdoctoral researcher, Yizhou Zhang, postdoctoral researcher, Dahin Kim and graduate student, Ruiqi Dong, as well as Xunda Feng of Donghua University, contributed to this work.

One challenge the team faced was the difficulty of maintaining membrane stability in organic solvents with different polarities. They selected molecular species, surfactants, that exhibited low solubility in organic fluids, and which could be effectively linked together chemically to provide the required stability. The surfactants self-assemble in water when they are above a certain concentration, and form a soft gel. Such self-assembly—the formation of an ordered state—as a function of concentration is referred to as lyotropic behavior: "lyo-" referring to solution, and "-tropic" referring to order. The gels thus formed are called lyotropic mesophases.

The membranes developed in this study were created by forming first forming lyotropic mesophases of the surfactant in water, spreading the soft gel as a thin film, and then using a chemical reaction to link the surfactants together to form a nanoporous polymer. The size of the pores in the polymer are set by the self-assembled structure of the lyotropic mesophase.

"At a certain concentration in an aqueous solution, the surfactant molecules aggregate and form cylindrical rods, and then those rods will self-assemble into a hexagonal structure, yielding a gel-like material," says Osuji. "One of the ways we can manipulate the permeability, or size of the pores in our membranes, is by changing the concentration and size of the surfactant molecules used to create the membrane itself. In this study, we manipulated both of those variables to tune our pore sizes from 1.2 nanometers down to 0.6 nanometers."

These membranes are compatible with organic solvents and can be tailored to address different separation challenges. Organic solvent nanofiltration can reduce the footprint of traditional thermal separation processes. The uniform pore size of the membranes developed here provide compelling advantages in terms of membrane selectivity, and ultimately, energy efficiency as well.

"A specific application for this technology is in biofuel production," says Osuji. "The isolation of water-miscible alcohols from bioreactors is a key step in the manufacturing of ethanol and butanol biofuels. Membrane separations can reduce the energy used in separation of the product alcohols or fuels, from the aqueous medium in the reactor. The use of membranes is particularly advantageous in smaller scale operations such as this, where distillation is not cost effective."

"Additionally, the manufacturing of many pharmaceutical products often involves several steps of synthesis in different solvent environments. Those steps require the transfer of a chemical intermediate from one solvent to another miscible solvent, making this new membrane a perfect solution to drug development filtration needs."

Next steps for their research involve both theory and practice. The team plans to develop new models for membrane rejection and permeability that address the unique flow pattern of solutions through their membranes as well as identify additional future applications for their tunable technology.

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New process aims to strip ammonia from wastewater

A dash of ruthenium atoms on a mesh of copper nanowires could be one step toward a revolution in the global ammonia industry that also helps the environment.

Collaborators at Rice University's George R. Brown School of Engineering, Arizona State University and Pacific Northwest National Laboratory developed the high-performance catalyst that can, with near 100% efficiency, pull ammonia and solid ammonia—aka fertilizer—from low levels of nitrates that are widespread in industrial wastewater and polluted groundwater.

A study led by Rice chemical and biomolecular engineer Haotian Wang shows the process converts nitrate levels of 2,000 parts per million into ammonia, followed by an efficient gas stripping process for ammonia product collection. The remaining nitrogen contents after these treatments can be brought down to "drinkable" levels as defined by the World Health Organization. 

"We fulfilled a complete water denitrification process," said graduate student Feng-Yang Chen. "With further water treatment on other contaminants, we can potentially turn industrial wastewater back to drinking water." 

Chen is one of three lead authors of the paper that appears in Nature Nanotechnology.

The study shows a promising alternative toward efficient processes for an industry that depends upon an energy-intensive process to produce more than 170 million tons of ammonia per year.

The researchers knew from previous studies that ruthenium atoms are champs at catalyzing nitrate-rich wastewater. Their twist was combining it with copper that suppresses the hydrogen evolution reaction, a way to produce hydrogen from water that in this case is an unwanted side effect.

"We knew that ruthenium was a good metal candidate for nitrate reduction, but we also knew there was a big problem, that it could easily have a competing reaction, which is hydrogen evolution," Chen said. "When we applied current, a lot of the electrons would just go to hydrogen, not the product we want."

"We borrowed a concept from other fields like carbon dioxide reduction, which uses copper to suppress hydrogen evolution," added Wang. "Then we had to find a way to organically combine ruthenium and copper. It turns out that dispersing single ruthenium atoms into the copper matrix works the best."

The team used density functional theory calculations to explain why ruthenium atoms make the chemical path that connects nitrate and ammonia easier to cross, according to co-corresponding author Christopher Muhich, an assistant professor of chemical engineering at Arizona State.

"When there is only ruthenium, the water gets in the way," Muhich said. "When there is only copper, there isn't enough water to provide hydrogen atoms. But on the single ruthenium sites water doesn't compete as well, providing just enough hydrogen without taking up spots for nitrate to react."

The process works at room temperature and under ambient pressure, and at what the researchers called an "industrial-relevant" nitrate reduction current of 1 amp per square centimeter, the amount of electricity needed to maximize catalysis rate. That should make it easy to scale up, Chen said.

"I think this has big potential, but it's been ignored because it's been hard for previous studies to reach such a good current density while still maintaining good product selectivity, especially under low nitrate concentrations," he said. "But now we're demonstrating just that. I'm confident we'll have opportunities to push this process for industrial applications, especially because it doesn't require big infrastructure."

A prime benefit of the process is the reduction of carbon dioxide emissions from traditional industrial production of ammonia. These are not insignificant, amounting to 1.4% of the world's annual emissions, the researchers noted.

"While we understood that converting nitrate wastes to ammonia may not be able to fully replace the existing ammonia industry in the short term, we believe this process could make significant contributions to decentralized ammonia production, especially in places with high nitrate sources," Wang said.

Alongside the new study, Wang's lab and that of Rice environmental engineer Pedro Alvarez, director of the Nanotechnology Enabled Water Treatment (NEWT) Center, recently published a paper in the Journal of Physical Chemistry C detailing the use of cobalt-copper nanoparticles on a 3D carbon fiber paper substrate as an efficient catalyst to synthesize ammonia from nitrate reduction. This low-cost catalyst also showed great promise for the denitrification in wastewater.

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Direct printing of nanodiamonds at the quantum level

Diamond nanocrystals, namely nanodiamonds, which host point defects such as nitrogen-vacancy (NV) centers, are a promising quantum material.

A central requirement to realize practical applications is the placement of individual NV centers at will on integrated circuits. This is critical for implementing quantum technologies, leading to a number of exciting opportunities and emerging fields such as quantum computers, quantum communications, and quantum metrology.

However, a flexible, universal route is still needed for achieving nanoscale accuracy, scalability, cost-effectiveness and efficient coupling with a wide range of nanophotonic circuitries.

Several methods, such as the sophisticated "pick-and-place" nanomanipulation approach, have been devised to position the nanodiamonds with NV centers on various substrates and circuits. However, this prerequisite continues to suffer from coarse positioning accuracy, low throughput, and process complexity.

The team led by Dr. Ji Tae Kim from the Department of Mechanical Engineering and Dr. Zhiqin Chu from the Electrical and Electronic Engineering of the University of Hong Kong (HKU) has developed a nano-precision printing method for nitrogen-vacancy (NV) centers in diamond at the quantum level, meeting the technological requirements.

This novel approach is practical and cost-effective, paving the way for manufacturing of quantum information processing device, quantum computing and biosensing devices.

The research achievement has been published in Advanced Science in an article titled "On-Demand, Direct Printing of Nanodiamonds at the Quantum Level."

The NV center is a point-defect in the diamond lattice and is the most common defect in nanodiamonds. It has emerged as a powerhouse for quantum systems due to their robust quantum states even at room temperature while other quantum systems such as superconducting quantum interference device can only operate at cryogenic temperatures, i.e., from -150 degrees C (-238 degrees F) to absolute zero (-273 degrees C or -460 degrees F).

Specifically, this atom-like, solid-state device, with its optically addressable spin-degrees-of-freedom, provides the key functionalities for serving as the quantum bit and/or quantum sensor in solid-state quantum processors.

'Diamond is the hardest material, so it is difficult to craft'

The researchers have developed an innovative way to tackle this issue. They have utilized electrical dispensing of nanodiamond-laden liquid droplets with sub-attoliter (< 10-18liter) volume for placing NV-centers directly on universal substrates.

"To the best of our knowledge, the developed technique, for the first time, shows sub-wavelength positional accuracy, single-defect-level quantity control, and freeform patterning capabilities, meeting the technological requirements which marks a significant breakthrough in quantum device manufacturing," said Dr. Chu Zhiqin.

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Anti-viral drugs can be final solution as WHO warns against lowering our guard to COVID-19

Suggestions that COVID-19 is on the wane have been strongly contradicted by the World Health Organization’s senior pandemics scientist, Dr Maria Van Kerkhove.

And her criticism of virus complacency has fuelled calls for research and development of anti-viral drugs to stop all coronaviruses at source, in addition to ongoing vaccines and testing for COVID-19 variants.

Dr Van Kerkhove, a highly regarded infectious disease epidemiologist and World Health Organization (WHO) Head of the Emerging Diseases and Zoonoses Unit, delivered her wake-up call in a BBC TV interview where she insisted that COVID-19 was still evolving and the world must evolve with it:

“It will not end with this latest wave (Omicron) and it will not be the last variant you will hear us (WHO) speaking about – unfortunately,” she told BBC interviewer Sophie Raworth.

Countries with high immunity and vaccination levels were starting to think the pandemic is over, she added, but despite 10 billion vaccine doses delivered globally, more than three billion people were yet to receive one dose, leaving the world highly susceptible to further COVID mutations - a global problem for which a global solution was needed.

She also challenged assumptions that the COVID Omicron variant was mild: “It is still putting people in hospital…and it will not be the last (variant). There is no guarantee that the next one will be less severe. We must keep the pressure up – we cannot give it a free ride.”

WNF Chairman Paul Stannard said: “We welcome Dr Van Kerkhove’s timely intervention. Too many people think we can sit back with COVID now, forgetting lessons learned the hard way.

“Such as there’s always another variant just around the corner, and testing and vaccines are not the complete answer.

“Even if Omicron seems milder than its predecessors – though this may be due to vaccinations and growing herd immunity – who can say that a more fatal COVID mutation will not follow, or an all-new virus is waiting to strike.

“Many other pathogens have entered humans in last 15 years including SARS, Ebola, Zika virus and Indian Flu variants, so permanent pandemic protection investment is vital to restoring confidence in our way of life and the global markets.

“An even older lesson is Spanish Flu (1918-20): the death toll was relatively contained initially, lulling people already fatigued by WW1 devastation into thinking the worst was over.

“But that virus then mutated into its most deadly strain, killing 50 million people when Earth’s population numbered less than two billion. All of which suggests we must maintain or redouble our efforts against COVID-19 and other potential threats.

“We have already benefitted from greater healthcare investment and research due to the pandemic: experts say the first six months of the emergency delivered sector progress equivalent to the previous 10 years.

“This helped unusually rapid deployment of new and better testing and vaccines that have driven down infection, hospitalization and deaths, but we hope that the WHO view will now foster a new and potentially more effective development against COVID and other threats – anti-viral drugs.

“Instead of attacking the virus like a vaccine, anti-viral drugs aim to stop it functioning in the human body. Merck and Pfizer say they have re-purposed existing drugs to do just that.

“But a better option is gathering momentum using nanomedicine, AI and advanced computational technology to develop all-new drugs more quickly and effectively, potentially delivering breakthroughs against many serious killers, including viruses, cancers and heart disease.

“WNF believes these can disrupt the traditional pharmaceutical industry as Tesla has done in the auto industry, or SpaceX and Blue Origin have done in space.”

California-based Verseon has developed an AI and computational drug development platform and has six drug candidates, including an anti-viral drug to potentially block all coronaviruses and some flu variants, potentially transforming pandemic protection.

This could be on the market within 18 months after securing a final $60 million investment, a small amount compared to the $1 billion pharma industry norm for a single new drug (source: Biospace), and weighed against 5.6 million COVID deaths globally and an estimated $3 trillion in economic output (source: Statista) lost since the start of the pandemic.

Verseon Head of Discovery Biology Anirban Datta said: “Vaccines and the current anti-viral drugs are retrospective solutions that don’t treat newly emergent strains. We need a different strategy to avoid always being one step behind viral mutations.

“So, we switched target from the virus to the human host. If we stop SARS-CoV-2 (COVID-19) entering our cells which, unlike viruses, don’t mutate then we have a long-term solution.

“Even better, the strategy should work against other coronaviruses and influenza strains that use the same mechanism as SARS-CoV-2 to infect cells – a key point, since it surely won’t be the last pandemic to affect humanity.”

Nanomedicine and AI computational drug delivery is key to beating never-ending COVID mutation cycle

As the world reels from the rise of another COVID-19 variant – the omicron strain – attention again rightly focuses on vaccine protection.

But the big question increasingly asked is: “Can this end the pandemic or do we always face being outflanked by the next new variant?”

Pfizer admitted this week that we could still be ‘managing’ COVID variants into 2024 as the virus moves, hopefully, from pandemic to endemic.

This suggests that the world desperately needs robust new anti-viral drugs that stop all coronaviruses at source, using the latest nanotechnology and AI drug discovery applications.

Industry experts admit that the current crop of mRNA vaccines represent a major step-up. Developed in record time, they have been highly effective in preventing symptoms, viral load and the spread of prior COVID-19 variants.

But viral mutations continue to degrade vaccine effectiveness, particularly for respiratory viruses like influenza and COVID-19.

And a large part of global society either can’t access, or worse, refuses vaccination, thereby enabling these viruses to mutate in unprotected hosts and perpetuate the ‘Groundhog Day’ nightmare that humanity keeps re-living.

In contrast, anti-viral drugs should be easier to distribute, more readily taken up, and protection of the majority is less likely to be compromised if certain people choose not to take the drugs. 

They work differently: instead of enabling the virus to mutate, they disrupt or block the process. One approach was described as “like putting diesel in a petrol engine,” according to a Daily Telegraph report quoting Stephen Griffin, associate professor in the School of Medicine, University of Leeds.

Established drug giants, Merck and Pfizer, recently announced COVID-19 anti-virals repurposed from prior programs, though questions have been raised about how long these drugs last in the body and their dosage frequency. 

Merck’s Molnupiravir – modified from an anti-flu drug - needs eight doses daily and while Pfizer’s Paxlovid only needs four, it must be partnered with an HIV drug to prevent the liver filtering it out before it can act.

There is still more to understand about their efficacy: although Paxlovid’s estimated effectiveness in preventing adverse outcomes such as severe illness or death remains high for now, Molnupiravir’s effectiveness has been revised down to potentially only 30%. 

It has also been suggested that they become less effective as the virus continues to mutate. All of which prompts three questions:

Firstly, are these drugs a better answer than vaccines? 

Secondly, rather than always playing catch-up with such viruses why not stop them entirely in the first place, through new drug discoveries? 

Thirdly, who will come up with such solutions?

Last week, Nano Magazine ran a major international report on new trends in nanomedicine and the use of AI and other technologies in drug discovery. 

Various companies were mentioned, including London-based BenevolentAI, which joined a public-private consortium to find treatments for COVID. 

BenevolentAI identified Baricitinib as an existing drug to repurpose for treating COVID-19, but according a report in The Lancet, the drug prevented just one additional death in every 20 Baricitinib-treated patients against a placebo batch in a later clinical trial.

Nano Magazine’s report also mentioned California-based Verseon as one of the more promising companies in drug discovery, and its Head of Discovery Biology Anirban Datta said:

“Vaccines and the current anti-viral drugs are retrospective solutions that don’t treat newly emergent strains. We need a different strategy to avoid always being one step behind viral mutations. 

“Verseon’s thinking is to focus on blocking the host mechanism through which SARS-CoV-2 (COVID-19) enters cells. Unlike viruses, the host’s cells don’t mutate, so going after the proteins on host cells that allow viral entry is a long-term solution. 

“Given the emergence of yet another highly infectious strain like omicron, we have just started a program at Verseon that does exactly that.”

Data added that other coronaviruses and influenza strains use the same mechanism as SARS-CoV-2 to infect cells – a key point, since it won’t be the last pandemic to affect humanity. 

Paul Stannard, Chairman of the World Nano Foundation said: “This is exactly why our not-for-profit organisation has put together an international consortium of investment partners for future pandemic protection and preparedness. 

“Because eventually encroachment on natural habitats, handling practices for living and butchered animals, or other issues will introduce yet another pathogen against which humans have no natural defense, so we are in a race against time to develop broad-spectrum antiviral drugs that block entry into our body cells.

And the stakes could be far higher next time, according to Dr. Mike Ryan Executive Director of the Health Emergencies Program at WHO (World Health Organization): 

“This pandemic has been very severe. It has affected every corner of this planet. But this is not necessarily the big one.”

Another anti-viral drug hit the headlines this week when the UK’s National Health Service (NHS) announced that it would deploy Sotrovinab, a GlaxoSmithKline anti-viral drug for clinically vulnerable patients, such as cancer patients, organ transplant recipients and other high-risk groups. 

Nanosensor and Digital Twin technologies come together at COP26 to help deliver a circular economy as part of the race to zero

Deploying billions of highly accurate and secure nanosensors interconnected to a global Digital Twin network can enable real-time monitorisation of emissions within urban and agricultural environments.

Nanosensors and Digital Twins are forecast to be pivotal to discussions between international nations and bodies at COP26 in Glasgow, the UK, from October 31st until November 12th and predicted to have a significant impact on the future of carbon tracking.

This technology collaboration will enable global organisations to reward organisations and people globally for tracking and managing emissions to reverse Climate Change while holding to account countries and industries that don't.

Sensors can be positioned in every urban and rural space, including major rainforests and polluting cities, allowing global carbon emission tracking with unprecedented real-time accuracy.

Digital Twin technology will calculate the carbon emission data gathered by nanosensors, providing a globally sharable, highly accurate representation of how countries, companies, households, and individuals manage emissions in a way that supports the creation of a circular economy - a key sustainability strategy for the world as well as industry leaders to fight climate change. 

This particular model for a circular economy is still evolving in terms of data and metrics, but indicators suggest this approach and enabling technologies such as Nanotechnology, and Digital Twins are vital to holding people to account while rewarding industry, governments, and the public for their work in driving down carbon emissions to net-zero.

Former Brazilian ambassador and diplomat and a Harvard scholar, Arnildo Schildt, has been developing a project based on this new model and will be presenting this at the COP26 summit in Glasgow, UK (October 31st to November 12th) – an event being billed as a catalyst for action and tech adoption in the Climate Change battle.

This project will use nanosensors to track deforestation and pollution to help accurately manage carbon credits and offsets, enabling the reduction of emissions and highly accurate tracking of data on deforestation.

Schildt said: "We have been working tirelessly now for two years developing a model with governments, the UN, international banks, academics and industry partners as well as investors to harness the power of Digital Twin and nanosensor technology to solve two massive challenges for our environment simultaneously. 

"We have a delegation going to COP26 and will follow this with other partnership meetings in the UK, Canada and the US straight after the Glasgow event to make this a reality."

Schildt's initiative in vital rural areas mirrors the urban and agricultural work conducted by US-based Cityzenith, which uses Digital Twin technology to decarbonise the built environment, tracking, managing, and reducing emissions in buildings across metropolitan areas and major international cities as well as linking this to carbon rewards, credits, and other global incentive programs for sustainability. 

Cityzenith was referenced by an independent global research group report from ABI research on the 28th of October, naming the company one of three, including The Ellen MacArthur Foundation and Vodafone, that can deliver the infrastructure required for a functional circular economy.

Currently, cities generate 70% of world emissions. Cityzenith’s international Clean Cities – Clean Future initiative has major world cities joining the program, using its Digital Twin platform SmartWorldOS to reduce carbon emissions in buildings by 50-100%, operating costs by 35% and increase productivity by 20%, another independent report by Ernst and Young on Digital Twins aligns with this. 

Las Vegas and New York were the first two cities to sign up, with projects in Phoenix and others expected to follow over the next few months.

Cityzenith CEO Michael Jansen said: "We are confident that the Clean Cities – Clean Future initiative will demonstrate the combined power of Digital Twin and IoT technology to transform mobility, walkability, and emissions/air pollution, while linking all of this to carbon rewards and other carbon related incentives via one interconnected Digital Twin platform.

"And COP26 can play a huge role in bringing the climate crisis into the public spotlight, by acknowledging and backing technologies such as Digital Twins and nanotechnology to make a difference in the fight to protect the planet."

The UK will also bring a national Digital Twin program to the summit through Anglian Water, BT, and UK Power Networks, which have partnered to foster better outcomes for the built environment.

The project aims to deliver an Information Management Framework which can ensure secure, resilient data sharing and effective information management. At the same time, the program identifies a range of benefits to society, business, the environment, and the broader economy.

Co-Founder of the World Nano Foundation, Paul Sheedy, said: 

"Nanotechnologies such as nanosensors and quantum dots can track and monitor anything, holding and transmitting infinite amounts of secure data around the world.

"Combining nanotechnology with advanced Digital Twin platforms is game-changing for the UN’s Sustainable Development Goals and ESG investors that support such impact investing."

Nanotechnology and Digital Twins were both named in 2021 as the top 5 tech growth sectors forecast to quadruple over the next five years; each sector is predicted to enjoy a combined growth of more than 400% in that time.