Nanoparticles are complex materials smaller than 100 nanometers, or about the size of a virus, but they have a large range of potential applications, from medicine to energy to electronics. Now, hundreds of new nanoparticles with previously unknown features have been produced using an innovative experimental approach.
This approach allowed them to discover novel nanoparticles, which combine many different materials in various arrangements. They then analyzed these nanoparticles to develop new guidelines that allowed them to make high-yield samples of the most interesting types of new nanoparticles.
Nanoparticles that can potentially be used to split water using sunlight, diagnose and treat cancer, and solve other important problems can be predicted and designed. These particles may need to include various types of semiconductors, catalysts, magnets, and other materials to function, all while maintaining strict requirements involving their size and shape.
“There are a certain number of rules that we and others have developed in this field that allow us to make a lot of different kinds of nanoparticles,” said Raymond Schaak, DuPont Professor of Materials Chemistry at Penn State and the leader of the research team.
“We can also predict, especially with the help of computers, tens of thousands of different nanoparticles that could be really interesting to study, but we have no clue how to make most of them. We need new rules that allow us to make nanoparticles with new properties, new functions, or new applications, and that allow us to better match the speed at which they can be predicted.”
The current set of rules, or design guidelines, available to researchers limits the variety of nanoparticles that they can produce, so the researchers set up experiments under unoptimized and previously unexplored conditions to see if they could make new types of particles that hadn’t previously been discovered.
“What we do can be described as ‘discovery without a target,'” said Connor R. McCormick, a graduate student in chemistry at Penn State and the first author of the paper.
“If you have a target in mind, you are trying to modulate the chemistry to make that target, but you need to know what factors to modulate—you need to know the rules—ahead of time. What is so exciting about our approach is that we are letting the chemistry guide us and show us what is possible. We can then characterize the products and discover what we can control in order to produce them intentionally.”
The researchers start with relatively simple rod-shaped nanoparticles composed of a single material, copper sulfide, which contains charged atoms (“cations”) of copper. They can then replace some or all of the copper in the particles with other metals using a process called “cation exchange.”
The arrangement of the metals in the particles and the interfaces between them determine the properties of the particles. Generally, this process is done one metal at a time using experimental conditions optimized to precisely control the cation exchange reaction. Here, in one experiment, the researchers added four different metal cations at the same time under conditions that were not optimized for any particular metal cation exchange. They then painstakingly characterized the resulting particles using electron microscopy and X-ray diffraction.
“Unlike most experiments, which are set up to converge on a single product, our goal was to set up the experiment in a way that maximized the diversity of nanoparticles that we produced,” said McCormick. “Of the 201 particles that we analyzed from one experiment, 102 were unique and many of them could not have been produced intentionally using existing design guidelines.”
The team then performed the experiment using slightly altered variables, changing the temperature of the reaction or the relative amount and variety of metal cations. By doing this, they produced even more complex nanoparticles and eventually were able to figure out the new rules that explained how the new types of nanoparticles had formed.
Finally, the team chose one of the new products and used the new design guidelines to efficiently produce it in larger quantities.
“Eventually, this approach could be used to screen for new particles with specific properties, but currently we are focusing on learning as much as we can about what all is possible to make,” said Schaak. “We’ve demonstrated that this exploratory approach can indeed help us to identify these ‘new rules’ and then use them to rationally produce new complex nanoparticles in high yield.”
The paper describing these experiments appears in the journal Nature Synthesis.
In a new study, scientists with the University of Florida have found that a combination of silver nanoparticles and antibiotics is effective against antibiotic-resistant bacteria. The researchers hope to turn this discovery into viable [...]
Peritoneal cancer is difficult to treat and has a poor survival prognosis. But a new and effective nanomedicine delivery system is offering some hope. The company is called NaDeNo and is well underway with [...]
According to a new study by researchers at Penn Medicine, ketamine, which is well-known as an anesthetic and is becoming increasingly popular as an antidepressant, dramatically reorganizes activity in the brain, almost as if [...]
A new immunotherapy releases cancer-killing cytokines only within the tumor. Researchers at the University of California San Francisco (UCSF) have developed a new T cell-based immunotherapy that selectively targets cancer cells, producing a powerful anti-cancer cytokine [...]
An AI was tasked with creating proteins with anti-microbial properties. Researchers then created a subset of the proteins and found some did the job. An AI has designed anti-microbial proteins that were then tested [...]
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 [...]
By one unique metric, we could approach technological singularity by the end of this decade, if not sooner. A translation company developed a metric, Time to Edit (TTE), to calculate the time it takes for professional [...]
Phase transition in early universe changes strength of interaction between dark and normal matter. Dark matter remains one of the greatest mysteries of modern physics. It is clear that it must exist, because without [...]
Summary: Researchers have developed a new family of nano-scale capsules capable of carrying CRISPR gene editing tools to different organs of the body before harmlessly dissolving. The capsules were able to enter the brains of [...]
An enzyme that defends human cells against viruses can help drive cancer evolution towards greater malignancy by causing myriad mutations in cancer cells, according to a study led by investigators at Weill Cornell Medicine. The [...]
Using a mouse model, Japanese researchers unleash the likely mechanism of action of Actinidia arguta (sarunashi) juice on lung cancer development. Lung cancer is a leading cause of death in Japan and across the [...]
When used as wearable medical devices, stretchy, flexible gas sensors can identify health conditions or issues by detecting oxygen or carbon dioxide levels in the breath or sweat. They also are useful for monitoring [...]
Novel drugs, such as vaccines against covid-19, among others, are based on drug transport using nanoparticles. Whether this drug transport is negatively influenced by an accumulation of blood proteins on the nanoparticle’s surface was [...]
The costly lesson from COVID: why elimination should be the default global strategy for future pandemics
Imagine it is 2030. Doctors in a regional hospital in country X note an expanding cluster of individuals with severe respiratory disease. Rapid whole-genome sequencing identifies the disease-causing agent as a novel coronavirus. Epidemiological [...]
A predictive model has been developed that enables researchers to encode instructions for cells to execute. Scientists at the University of California, San Francisco (UCSF) and IBM Research have created a virtual library of thousands of “command sentences” [...]
It's "lights out" for antibiotic-resistant superbugs as next-generation light-activated nanotech proves it can eradicate some of the most notorious and potentially deadly bacteria in the world. Developed by the University of South Australia and [...]