Zhao, N., Zhang, CJ., Zhang, X. et al. npj Regen Med 9, 42 (2024). https://doi.org/10.1038/s41536-024-00387-7
Category: chemistry – Page 8
Chemical Sensing.
RNA aptamers light up after ligand reacts.
Designing an organic reaction that works in cells is easier than designing a riboswitch, chemist says.
Researchers have successfully stabilized ferrocene molecules on a flat substrate for the first time, enabling the creation of an electronically controllable sliding molecular machine.
Artificial molecular machines, composed of only a few molecules, hold transformative potential across diverse fields, including catalysis, molecular electronics, medicine, and quantum materials. These nanoscale devices function by converting external stimuli, such as electrical signals, into controlled mechanical motion at the molecular level.
Ferrocene—a unique drum-shaped molecule featuring an iron (Fe) atom sandwiched between two five-membered carbon rings—is a standout candidate for molecular machinery. Its discovery, which earned the Nobel Prize in Chemistry in 1973, has positioned it as a foundational molecule in this area of study.
Exploiting an ingenious combination of photochemical (i.e., light-induced) reactions and self-assembly processes, a team led by Prof. Alberto Credi of the University of Bologna has succeeded in inserting a filiform molecule into the cavity of a ring-shaped molecule, according to a high-energy geometry that is not possible at thermodynamic equilibrium. In other words, light makes it possible to create a molecular “fit” that would otherwise be inaccessible.
“We have shown that by administering light energy to an aqueous solution, a molecular self-assembly reaction can be prevented from reaching a thermodynamic minimum, resulting in a product distribution that does not correspond to that observed at equilibrium,” says Alberto Credi.
“Such a behavior, which is at the root of many functions in living organisms, is poorly explored in artificial molecules because it is very difficult to plan and observe. The simplicity and versatility of our approach, together with the fact that visible light—i.e., sunlight—is a clean and sustainable energy source, allow us to foresee developments in various areas of technology and medicine.”
This groundbreaking approach could revolutionize technology and medicine by leveraging sunlight to develop innovative materials, smart drugs, and dynamic systems mimicking the non-equilibrium processes in living organisms.
Harnessing Light for Molecular Manipulation
Using a creative combination of light-driven (photochemical) reactions and molecular self-assembly, a research team led by Prof. Alberto Credi at the University of Bologna has achieved a groundbreaking feat. They successfully inserted a thread-like molecule into the cavity of a ring-shaped molecule, forming a high-energy structure that would normally be impossible under thermodynamic equilibrium. In essence, light enables the creation of molecular configurations that nature cannot achieve on its own.
Smartwatch bands from popular brands have been found to contain high concentrations of toxic for forever chemicals, also known as PFAS (per-and polyfluoroalkyl substances). These synthetic chemicals do not break down easily in the environment and build in our bodies over time, hence earning them the nickname of forever chemicals.
PFAS are used in various consumer products, including non-stick cookware, water-resistant clothes, carpets, mattresses, food wraps, and more. Exposure to PFAS has been linked to serious health problems, including increased risks of certain cancers, hormone disruption, weakened immune systems, and developmental delays in children. These chemicals can leach into water, soil, and food, making them a growing public health concern worldwide.
A new study published in the journal Environmental Science & Technology Letters has found that smartwatch bands made of fluoroelastomers contain a very high concentration of a forever chemical known as perfluorohexanoic acid (PFHxA).
Stanford and Seoul National University researchers have developed an artificial sensory nerve system that can activate the twitch reflex in a cockroach and identify letters in the Braille alphabet.
The work, reported May 31 in Science, is a step toward creating artificial skin for prosthetic limbs, to restore sensation to amputees and, perhaps, one day give robots some type of reflex capability.
“We take skin for granted but it’s a complex sensing, signaling and decision-making system,” said Zhenan Bao, a professor of chemical engineering and one of the senior authors. “This artificial sensory nerve system is a step toward making skin-like sensory neural networks for all sorts of applications.”
Human evolution is linked to the manipulation of the environment. Since the first hominid to use a stone as a tool — or a bone according to the iconic scene from 2001: A Space Odyssey —, we have come to recognise this as materials science. This discipline uses physics, chemistry and engineering to study how materials are formed and what their physical properties are, as well as to discover and develop new materials, such as smart materials in order to find new uses applicable to any sector.
Smart materials are materials that are manipulated to respond in a controllable and reversible way, modifying some of their properties as a result of external stimuli such as certain mechanical stress or a certain temperature, among others. Because of their responsiveness, smart materials are also known as responsive materials. These are usually translated as “active” materials although it would be more accurate to say “reactive” materials.
For example, we can talk about sportswear with ventilation valves that react to temperature and humidity by opening when the wearer breaks out in a sweat and closing when the body cools down, about buildings that adapt to atmospheric conditions such as wind, heat or rain, or about drugs that are released into the bloodstream as soon as a viral infection is detected.
Glass might soon have some competition from an unlikely rival – bamboo. Scientists in China have turned regular old bamboo into a transparent material that’s also resistant to fire and water, and suppresses smoke.
Silica glass, made from sand, is still the go-to building material when you need something transparent but strong, like windows. But it’s not particularly sustainable, and can be heavy and brittle.
Transparent wood has actually been muscling in on glass’s turf for a few years now. Scientists chemically remove the lignin from the wood fibers, then treat the remaining material with plexiglass or epoxy. The end result is a material that’s transparent, renewable, and as strong as or stronger than glass, while being lighter and a better thermal insulator.
Electrons, those fundamental particles that orbit atomic nuclei, are central to electromagnetism and chemical processes. Ever since their discovery, scientists have pondered over what electrons are made of and their basic structure. While particles such as protons and neutrons have shown internal complexity, electrons appear impenetrable to such analysis. So, what constitutes an electron? Are they truly indivisible, or do they hide smaller components within?
Speaking of the atom, the term “indivisible” now seems outdated, especially with modern scientific understanding. The notion that atoms are the most fundamental units of matter dates back to Democritus over 2,000 years ago. However, as centuries passed and scientific discoveries unfolded, it became clear that atoms were not the ultimate particles of matter. Indeed, advancements in physics have shown that atoms are made up of even smaller particles: protons, neutrons, and electrons. While protons and neutrons can be broken down into quarks, the question remains for electrons: are they also made of smaller components, or are they indivisible?
Since their discovery over 125 years ago, electrons have challenged the logic of decomposition. No experiment has yet detected any more complex internal structure, even during high-energy collisions aimed at probing deeper levels of matter. Electrons thus seem to defy the notion of being made up of smaller particles. They are currently regarded as fundamental particles within the standard model of particle physics, meaning they are entities that cannot be divided further.