Nanotubes as an optical stopwatch for the detection of messenger substances

Bochum research team: Linda Sistemich and Sebastian Kruß
Photo Credit: © RUB, Kramer

Carbon nanotubes not only lighten in the presence of dopamine, but also longer. The lighting duration can serve as a new measurement for the detection of messenger substances.

An interdisciplinary research team from Bochum and Duisburg has found a new way to detect the important messenger substance dopamine in the brain. The researchers used carbon nanotubes for this. In previous studies, the team led by Prof. Dr. Sebastian Kruß has already shown that the tubes light up in the presence of dopamine. Now the interdisciplinary group showed that the duration of the lighting also changes. "It is the first time that an important messenger like dopamine has been detected in this way," says Sebastian Kruß. “We are convinced that this will open up a new platform that will also enable better detection of other human messenger substances such as serotonin. "The work was a cooperation between Kruß’ two working groups in physical chemistry at the Ruhr University Bochum and the Fraunhofer Institute for Microelectronic Circuits and Systems (IMS).

The results are described by a team led by Linda Sistemich and Sebastian Kruß from the Ruhr University Bochum together with colleagues from the IMS and the University of Duisburg-Essen in the journal Angewandte Chemie - International Edition, published online on 9. March 2023.

Watch nanoparticles grow into crystals

Liquid-phase TEM video of layer-by-layer growth of a crystal with smooth surface from gold concave nanocubes. Surface particles on the growing crystal are tracked (center positions overlaid with yellow dots).

For the first time ever, researchers have watched the mesmerizing process of nanoparticles self-assembling into solid materials. In the stunning new videos, particles rain down, tumble along stairsteps and slide around before finally snapping into place to form a crystal’s signature stacked layers.

Led by Northwestern University and the University of Illinois, Urbana-Champaign, the research team says these new insights could be used to design new materials, including thin films for electronic applications.

The research was published today (March 30) in the journal Nature Nanotechnology. 

Described by the researchers as an “experimental tour de force,” the study used a newly optimized form of liquid-phase transmission electron microscopy (TEM) to gain unprecedented insights into the self-assembly process. Before this work, researchers used microscopy to watch micron-sized colloids — which are 10 to 100 times larger than nanoparticles — self-assemble into crystals. They also have used X-ray crystallography or electron microscopy to visualize single layers of atoms in a crystalline lattice. But they were unable to watch atoms individually move into place.

“We know that atoms use a similar scheme to assemble into crystals, but we have never seen the actual growth process,” said Northwestern’s Erik Luijten, who led the theoretical and computational work to explain the observations. “Now we see it coming together right in front of our eyes. By viewing nanoparticles, we are watching particles that are larger than atoms, but smaller than colloids. So, we have completed the whole spectrum of length scales. We are filling in the missing length.”

Ultrasmall swirling magnetic vortices detected in iron-containing material

Simulation capturing the different swirling textures of skyrmions and merons observed in ferromagnet thin film.
Image Credit: University of Edinburgh/based on microscopy images collected by Argonne on samples prepared at MagLab

Microelectronics forms the foundation of much modern technology today, including smartphones, laptops and even supercomputers. It is based on the ability to allow and stop the flow of electrons through a material. Spin electronics, or spintronics, is a spinoff. It is based on the spin of electrons, and the fact that the electron spin along with the electric charge creates a magnetic field.

“This property could be exploited for building blocks in future computer memory storage, brain-like and other novel computing systems, and high-efficiency microelectronics,” said Charudatta Phatak, group leader in the Materials Science division at the U.S. Department of Energy’s (DOE) Argonne National Laboratory.

A team including researchers at Argonne and the National High Magnetic Field Laboratory (MagLab) discovered surprising properties in a magnetic material of iron, germanium and tellurium. This material is in the form of a thin sheet that is only a few to 10 atoms in thickness. It is called a 2D ferromagnet.

The team discovered that two kinds of magnetic fields can coexist in this ultrathin material. Scientists call them merons and skyrmions. They are like miniature swirling storm systems dotting the flat landscape of the ferromagnet. But they differ in their size and swirling behavior.

New wood-based technology removes 80 percent of dye pollutants in wastewater

Researchers at Chalmers have developed a new biobased material, a form of powder based on cellulose nanocrystals to purify water from pollutants, including textile dyes. When the polluted water passes through the filter with cellulose powder, the pollutants are absorbed, and the sunlight entering the treatment system causes them to break down quickly and efficiently. Laboratory tests have shown that at least 80 percent of the dye pollutants are removed with the new method and material, and the researchers see good opportunities to further increase the degree of purification.
Illustration Credit: David Ljungberg | Chalmers University of Technology

Clean water is a prerequisite for our health and living environment, but far from a given for everyone. According to the WHO, there are currently over two billion people living with limited or no access to clean water.

This global challenge is at the center of a research group at Chalmers University of Technology, which has developed a method to easily remove pollutants from water. The group, led by Gunnar Westman, Associate Professor of Organic Chemistry, focuses on new uses for cellulose and wood-based products and is part of the Wallenberg Wood Science Center.

The researchers have built up solid knowledge about cellulose nanocrystals* – and this is where the key to water purification lies. These tiny nanoparticles have an outstanding adsorption capacity, which the researchers have now found a way to utilize.

“We have taken a unique holistic approach to these cellulose nanocrystals, examining their properties and potential applications. We have now created a biobased material, a form of cellulose powder with excellent purification properties that we can adapt and modify depending on the types of pollutants to be removed,” says Gunnar Westman.

Purifying water with the power of the sun

A Notre Dame researcher’s invention could improve access to clean water for some of the world’s most vulnerable people.

 “Today, the big challenges are information technology and energy,” says László Forró, the Aurora and Thomas Marquez Professor of Physics of Complex Quantum Matter in the University of Notre Dame's Department of Physics and Astronomy. “But tomorrow, the big challenge will be water.”

The World Health Organization reports that today nearly 2 billion people regularly consume contaminated water. It estimates that by 2025 half of the world’s population could be facing water scarcity. Many of those affected are in rural areas that lack the infrastructure required to run modern water purifiers, while many others are in areas affected by war, natural disasters or pollution. There is a greater need than ever for innovative ways to extend water access to those living without power, sanitation and transportation networks.

Recently, Forró's lab developed just such a solution. They created a water purifier, described in the Nature partner journal Clean Water, that is powered by a resource nearly all of the world’s most vulnerable people have access to: the sun.

Ultrafast beam-steering breakthrough at Sandia Labs

As a red beam of light is reflected in an arch, Prasad Iyer, right, and Igal Brener demonstrate optical hardware used for beam steering experiments at Sandia National Laboratories’ Center for Integrated Nanotechnologies.
Photo Credit: Craig Fritz

In a major breakthrough in the fields of nanophotonics and ultrafast optics, a Sandia National Laboratories research team has demonstrated the ability to dynamically steer light pulses from conventional, so-called incoherent light sources.

This ability to control light using a semiconductor device could allow low-power, relatively inexpensive sources like LEDs or flashlight bulbs to replace more powerful laser beams in new technologies such as holograms, remote sensing, self-driving cars and high-speed communication.

“What we’ve done is show that steering a beam of incoherent light can be done,” said Prasad Iyer, Sandia scientist and lead author of the research, which was reported in the current issue of the journal Nature Photonics. 

Incoherent light is emitted by many common sources, such as an old-fashioned incandescent light bulb or an LED bulb. This light is called incoherent since the photons are emitted with different wavelengths and in a random fashion. A beam of light from a laser, however, does not spread and diffuse because the photons have the same frequency and phase and is thus called coherent light.

For the first time, controlling the degree of twist in nanostructured particles

An array of different growth conditions, spanning from left-handed twists made with only left-handed cystine to flat pancakes made with a 50-50 mix to right-handed twists made only with right-handed cystine. The ability to control the degree of twist in a curling, nanostructured material could be a useful new tool in chemistry and machine vision.
Image Credit: Prashant Kumar, Kotov Lab, University of Michigan.

Being able to decide not only whether a micron-scale particle twists but also how much could open new avenues for machine vision and more

Micron-sized “bow ties,” self-assembled from nanoparticles, form a variety of different curling shapes that can be precisely controlled, a research team led by the University of Michigan has shown.

The development opens the way for easily producing materials that interact with twisted light, providing new tools for machine vision and producing medicines.

While biology is full of twisted structures like DNA, known as chiral structures, the degree of twist is locked in—trying to change it breaks the structure. Now, researchers can engineer the degree of twist.

Such materials could enable robots to accurately navigate complex human environments. Twisted structures would encode information in the shapes of the light waves that reflect from the surface, rather than in the 2D arrangement of symbols that comprise most human-read signs. This would take advantage of an aspect of light that humans can barely sense, known as polarization. The twisted nanostructures preferentially reflect certain kinds of circularly polarized light, a shape that twists as it moves through space.

New kind of transistor could shrink communications devices on smartphones

Electrical & Computer Engineering research scientist Ding Wang and graduate student Minming He from Prof. Zetian Mi’s group, University of Michigan, are working on the epitaxy and fabrication of high electron mobility transistors (HEMTs) based on a new nitride material, ScAlN, which has been demonstrated recently as a promising high-k and ferroelectric gate dielectric that can foster new functionalities and boost device performances.”
Photo Credit: Marcin Szczepanski/Lead Multimedia Storyteller, Michigan Engineering

Integrating a new ferroelectric semiconductor, it paves the way for single amplifiers that can do the work of multiple conventional amplifiers, among other possibilities

One month after announcing a ferroelectric semiconductor at the nanoscale thinness required for modern computing components, a team at the University of Michigan has demonstrated a reconfigurable transistor using that material.

The study is a featured article in Applied Physics Letters.

“By realizing this new type of transistor, it opens up the possibility for integrating multifunctional devices, such as reconfigurable transistors, filters and resonators, on the same platform—all while operating at very high frequency and high power,” said Zetian Mi, U-M professor of electrical and computer engineering who led the research, “That’s a game changer for many applications.”

Nanotube sensors are capable of detecting and distinguishing gibberellin plant hormones

The continued study of gibberellins could lead to further breakthroughs in agricultural science and have implications for food security.
Photo Credit: Courtesy of SMART.

Researchers from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) interdisciplinary research group of the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, and their collaborators from Temasek Life Sciences Laboratory have developed the first-ever nanosensor that can detect and distinguish gibberellins (GAs), a class of hormones in plants that are important for growth. The novel nanosensors are nondestructive, unlike conventional collection methods, and have been successfully tested in living plants. Applied in the field for early-stage plant stress monitoring, the sensors could prove transformative for agriculture and plant biotechnology, giving farmers interested in high-tech precision agriculture and crop management a valuable tool to optimize yield.

The researchers designed near-infrared fluorescent carbon nanotube sensors that are capable of detecting and distinguishing two plant hormones, GA3 and GA4. Belonging to a class of plant hormones known as gibberellins, GA3 and GA4 are diterpenoid phytohormones produced by plants that play an important role in modulating diverse processes involved in plant growth and development. GAs are thought to have played a role in the driving forces behind the “green revolution” of the 1960s, which was in turn credited with averting famine and saving the lives of many worldwide. The continued study of gibberellins could lead to further breakthroughs in agricultural science and have implications for food security.

New Fluorescent Sensors Make it Possible to Detect the Concentration of Mercury in Water

New fluorophores selectively and with high sensitivity recognize mercury ions.
Photo Credit: Anna Marinovich

Scientists from the UrFU, together with Italian and Bulgarian colleagues, synthesized new heterocyclic fluorophores - four types of carboxamides of 2-aryl-1,2,3-triazoles. Their photophysical properties have been investigated under different conditions - solvents and their binary mixtures with water. Sensors based on the fluorophores obtained were sensitive to mercury, so they can be used to detect mercury concentrations in water. Further research will focus on determining the possibility of using these fluorophores to target medicines to affected organs. The authors have published an article on their research and results in the journal Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy.

"A disadvantage of organic fluorophores is their poor solubility in water and aqueous environments. At the same time, when water is added to organic solvents, most dyes and fluorophores have fluorescence quenching. However, in 2001, Professor Ben Zhong Tan of the Chinese University of Hong Kong found that some fluorophores observed not quenching, but rather an increase the fluorescence intensity. This is due to the formation of much larger particles, or nano-aggregates, from the molecules of fluorophores. Tan's discovery was of great significance. Much scientific effort has been devoted to studying the mechanism of his discovery, as well as to the design and synthesis of new fluorophores with the effect of increasing the emission. The fluorophores we obtained have also demonstrated in a mixture of organic solvent and water the effect described by Tang, and with a particular intensity. This opens the way to the practical application of the obtained fluorophores in various fields, especially in the aquatic environment," says Natalya Belskaya, Full Professor of the UrFU Department of Technology of Organic Synthesis and leader of the research team.

Light-Induced Acceleration of Intracellular Delivery

Conceptual image of various cellular uptake processes accelerated by light irradiation
Illustration Credit: Courtesy of Osaka Metropolitan University

Light-induced accelerating system to increase the concentration of bio- functional molecules around targeted cells and their cytosolic delivery.

Cell membranes are barriers that maintain cellular homeostasis, and the intracellular delivery of biologically functional molecules, including peptides, proteins, and nucleic acids to manipulate cellular functions. Conventional intracellular uptake processes require high concentrations of bio functional molecules with low permeability to pass through the cell membrane. This results in low drug activity because the probability of the bio-functional molecules entering target cells and their organelles is low. In addition, many drugs damage healthy cells as well as the cells that are supposed to target due to poor selectivity, making it necessary to develop technology that can increase drugs’ selectivity so that they enter targeted cells with high efficiency.

A research group led by Professor Ikuhiko Nakase (Assistant Director) and Professor Takuya Iida (Director) of the Research Institute for Light-induced Acceleration System (RILACS) at Osaka Metropolitan University used light-induced convection with the aid of superradiance to achieve enhanced permeability of the cell membrane, by locally concentrating bio-functional molecules, including cell-penetrating peptides (CPPs). The light-induced system was capable of effective drug delivery, even at concentrations as low as 1 pmol/L.

Chemical imaging could help predict efficacy of radiation therapy for an individual cancer patient

Concept illustration of body chemistry.
Image Credit: Nicole Smith, made with Midjourney. Courtesy of University of Michigan

Decisions on cancer treatment could become better tailored to individual patients with the adoption of a new imaging method being developed by University of Michigan researchers that maps the chemical makeup of a patient’s tumor.

Today, treatment methods for cancer—whether surgery, radiation therapy or immunotherapy—are recommended based mainly on the tumor’s location, size and aggressiveness. This information is usually obtained by anatomical imaging—MRI or CT scans or ultrasound and by biological assays performed in tissues obtained by tumor biopsies.

Yet, the chemical environment of a tumor has a significant effect on how effective a particular treatment may be. For example, a low oxygen level in tumor tissue impairs the effectiveness of radiation therapy.

Now, a team of scientists from the University of Michigan and two universities in Italy has demonstrated that an imaging system that uses special nanoparticles can provide a real-time, high-resolution chemical map that shows the distribution of chemicals of interest in a tumor.

It could lead to a way to help clinicians make better recommendations on cancer therapy tailored to a particular patient—precision medicine.

Chaos on the Nanometer Scale

Nanochaos on an asymmetric Rhodium nanocrystal
Illustration Credit: Vienna University of Technology

Sometimes, chemical reactions do not solely run stationary in one direction, but they show spatio-temporal oscillations. At TU Wien, a transition to chaotic behavior on the nanometer scale has now been observed.

Chaotic behavior is typically known from large systems: for example, from weather, from asteroids in space that are simultaneously attracted by several large celestial bodies, or from swinging pendulums that are coupled together. On the atomic scale, however, one does normally not encounter chaos – other effects predominate. Now, for the first time, scientists at TU Wien have been able to detect clear indications of chaos on the nanometer scale – in chemical reactions on tiny rhodium crystals. The results have been published in the journal Nature Communications.

Researchers find thermal limits of advanced nanomaterials

Boron nitride nanotube material in a crucible for heating at Florida State University's High-Performance Materials Institute.
Photo Credit: Mark Wallheiser/FAMU-FSU Engineering

A team of FAMU-FSU College of Engineering researchers at the High-Performance Materials Institute is exploring the thermal limits of advanced nanomaterials, work that could have a direct impact on medicine delivery systems, electronics, space travel and other applications.

The research team, led by Assistant Professor in Industrial and Manufacturing Engineering Rebekah Sweat, completed the first-ever study on how purified boron nitride nanotubes remain stable in extreme temperatures in inert environments.

Their work was published in the journal Applied Nano Materials.

Boron nitride nanotubes, or BNNTs, are stronger and more resistant to high temperatures than carbon nanotubes. Like their carbon cousins, they are structures measured by the nanometer — a length equal to one-billionth of a meter.

Packaged DNA: MLU researchers develop new method to promote bone growth

Image Credit: Sangharsh Lohakare

DNA can help to stimulate bone healing in a localized and targeted manner, for example after a complicated fracture or after severe tissue loss following surgery. This has been demonstrated by researchers at Martin Luther University Halle-Wittenberg (MLU), the University of Leipzig, the University of Aveiro (Portugal) and the Fraunhofer Institute for Microstructure of Materials and Systems IMWS in Halle. They have developed a new process in which they coat implant materials with a gene-activated biomaterial that induces stem cells to produce bone tissue. Their findings were published in the renowned journal Advanced Healthcare Materials.

Bones are a fascinating example of the body’s ability to regenerate. They are able to regain full functionality - even after a fracture - thanks to their ability to form new, resilient tissue at the fracture site. "However, when it comes to complicated fractures or major tissue loss, even a bone’s self-healing power is insufficient," explains Professor Thomas Groth, head of the Biomedical Materials research group at MLU’s Institute of Pharmacy. "In such cases, implants are needed to stabilize the bone, replace parts of joints, or bridge larger defects with degradable materials." The success of such implants depends largely on how well they are incorporated into the bone. Increased efforts have been made in recent years to support this process by coating implants with bioactive materials to activate bone cells and mesenchymal stem cells. 

Molecular machines could treat fungal infections

Schematic representation of the mechanisms by which light-activated molecular machines kill fungi. Molecular machines bind to fungal mitochondria, decreasing adenosine triphosphate (ATP) production and impairing the function of energy-dependent transporters that control the movement of ions, such as calcium. This leads to the influx of water, which causes the organelles to swell and eventually the cells to burst.
Image Credit: Tour Group/Rice University

That stubborn athlete’s foot infection an estimated 70% of people get at some point in their life could become much easier to get rid of thanks to nanoscale drills activated by visible light.

Proven effective against antibiotic-resistant infectious bacteria and cancer cells, the molecular machines developed by Rice University chemist James Tour and collaborators are just as good at combating infectious fungi, according to a new study published in Advanced Science.

Based on the work of Nobel laureate Bernard Feringa, the Tour group’s molecular machines are nanoscale compounds whose paddlelike chain of atoms moves in a single direction when exposed to visible light. This causes a drilling motion that allows the machines to bore into the surface of cells, killing them.

New type of solar cell is being tested in space

Magnus Borgström Professor, Solid State Physics Lund University
Photo Credit: Lund University

Physics researchers at Lund University in Sweden recently succeeded in constructing small solar radiation-collecting antennas – nanowires – using three different materials that are a better match for the solar spectrum compared with today’s silicon solar cells. As the nanowires are light and require little material per unit of area, they are now to be installed for tests on satellites, which are powered by solar cells and where efficiency, in combination with low weight, is the most important factor. The new solar cells were sent into space a few days ago.

A group of nanoengineering researchers at Lund University working on solar cells made a breakthrough last year when they succeeded in building photovoltaic nanowires with three different band gaps. This, in other words, means that one and the same nanowire consists of three different materials that react to different parts of solar light. The results have been published in Materials Today Energy and subsequently in more detail in Nano Research.

“The big challenge was to get the current to transfer between the materials. It took more than ten years, but it worked in the end,” says Magnus Borgström, professor of solid-state physics, who wrote the articles with the then doctoral student Lukas Hrachowina.

Targeting cancer with a multidrug nanoparticle

MIT chemists designed a bottlebrush-shaped nanoparticle that can be loaded with multiple drugs, in ratios that can be easily controlled.
Illustration Credit: Courtesy of the researchers. Edited by MIT News.

Treating cancer with combinations of drugs can be more effective than using a single drug. However, figuring out the optimal combination of drugs, and making sure that all of the drugs reach the right place, can be challenging.

To help address those challenges, MIT chemists have designed a bottlebrush-shaped nanoparticle that can be loaded with multiple drugs, in ratios that can be easily controlled. Using these particles, the researchers were able to calculate and then deliver the optimal ratio of three cancer drugs used to treat multiple myeloma.

“There’s a lot of interest in finding synergistic combination therapies for cancer, meaning that they leverage some underlying mechanism of the cancer cell that allows them to kill more effectively, but oftentimes we don’t know what that right ratio will be,” says Jeremiah Johnson, an MIT professor of chemistry and one of the senior authors of the study.

Scientists Suggest New Approach to Targeted Treatment of Bacterial Infections

Photo Source: Ural Federal University

It is based on the nanosystem with polyoxometalate

Chemists from the Ural Federal University have proposed a new approach to targeted treatment of affected areas of the human body, in particular, bacterial infections. It is based on a nanosystem, the core of which is polyoxometalate (containing molybdenum and iron). A broad-spectrum antibiotic, tetracycline, is attached to the surface of the polyoxometalate. This approach makes it possible to fight bacteria more effectively by targeting them. The results of the study are published in the journal Inorganics.

"The polyoxometalate ion is a charged nanoparticle that can be used as a base. It is very small - 2.5 nanometers. This allows it to easily penetrate cells and the walls of blood vessels. Drugs and additional substances (vector molecules) can be "planted" on it to help the system reach a specific affected organ. In this case, the drug is distributed less throughout the rest of the body. This reduces side effects, especially of highly toxic drugs," explains Margarita Tonkushina, a Researcher at the Section of Chemical Material Science and the Laboratory of Functional Design of Nanoclusters of Polyoxometalates at UrFU.

New method for designing tiny 3D materials could make fuel cells more efficient

Authors of the study Professor Richard Tilley and Dr Lucy Gloag.
Photo Credit: UNSW Sydney / Courtesy of the researchers 

Researchers have developed an innovative technique for creating nanoscale materials with unique chemical and physical properties.

Scientists from UNSW Sydney have demonstrated a novel technique for creating tiny 3D materials that could eventually make fuel cells like hydrogen batteries cheaper and more sustainable.

In the study published in Science Advances, researchers from the School of Chemistry at UNSW Science show it’s possible to sequentially ‘grow’ interconnected hierarchical structures in 3D at the nanoscale which have unique chemical and physical properties to support energy conversion reactions.

In chemistry, hierarchical structures are configurations of units like molecules within an organization of other units that themselves may be ordered. Similar phenomena can be seen in the natural world, like in flower petals and tree branches. But where these structures have extraordinary potential is at a level beyond the visibility of the human eye – at the nanoscale.