Nanoparticles are everywhere. They are in our body as protein aggregates, lipid vesicles, or viruses. They are in our drinking water in the form of impurities. They are in the air we breath as pollutants. At the same time, many drugs are based on the delivery of nanoparticles, including the vaccines we have been recently given. | |
Keeping with the pandemics, quick tests used for the detection the SARS-Cov-2 are based on nanoparticles too. The red line, which we monitor day by day, contains myriads of gold nanoparticles coated with antibodies against proteins that report infection. | |
Technically, one calls something a nanoparticle when its size (diameter) is smaller than one micrometer (one thousandth of a millimeter). Objects of the order of one micrometer can still be measured in a normal microscope, but particles that are much smaller, say smaller than 0.2 micrometers, become exceedingly difficult to measure or characterize. Interestingly, this is also the size range of viruses, which can become as small as 0.02 micrometers. |
Over the years, scientists and engineers have devised a number of instruments for characterizing nanoparticles. Ideally, one wants to measure their concentration, assess their size and size distribution, and determine their substance. A high-end example is an electron microscope. | |
But this technology has many shortcomings. It is very bulky and expensive, and the studies take too long because samples have to be carefully prepared and be put into vacuum. And even then, it remains difficult to determine the substance of the particles one sees in an electron microscope. | |
A quick, reliable, light and portable device that can be used in the doctor’s office or in the field would have a huge impact. A few optical instruments on the market offer such solutions, but their resolution and precision have been insufficient for examining smaller nanoparticles, e.g., much smaller than 0.1 micrometer (or otherwise said 100 nm). | |
A group of researchers at the Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und Medizin have now invented a new device that offers a big leap in the characterization of nanoparticles. The method is called iNTA, short for Interferometric Nanoparticle Tracking Analysis. | |
Their results are reported in the May issue of Nature Methods (“Precision size and refractive index analysis of weakly scattering nanoparticles in polydispersions”). |
The method is based on the interferometric detection of the light scattered by individual nanoparticles that wander around in a liquid. In such a medium, thermal energy perpetually moves particles in random directions. It turns out that the space that a particle explores in a given time correlates with its size. In other words, small particles move “faster” and cover a bigger volume than large particles. | |
The equation that describes this phenomenon – the Stokes-Einstein relation – dates back to the beginning of the last century and since then has found use in many applications. In a nutshell, if one could follow a nanoparticle and collect statistics about its jittery trajectory, one could deduce its size. So, the challenge is to record very fast movies of tiny particles wizzing by. | |
Scientists at MPL have developed a special microscopy method over the past two decades, known as interferometric scattering (iSCAT) microscopy. This technique is extremely sensitive in detecting nanoparticles. By applying iSCAT to the problem of diffusing nanoparticles, the MPL group realized that they can outperform the existing instruments on the market. The new technology has a particular edge in deciphering mixtures of nanoparticles with different sizes and different materials. | |
The applications of the new method are manifold. A particularly exciting line of applications concerns nano-sized vehicles that are secreted from cells, the so-called extracellular vesicles. These are made of a lipid shell, much like a nano soap bubble. But the shell and the inner liquid also contain proteins, which tell us about the origin of the vesicles, i.e. from which organ or cellular process. When the protein amount and/or the vesicle size deviate from the normal range, it could be that the person is ill. Therefore, it is very important to find ways to characterize extracellular vesicles. | |
The researchers at the MPL and MPZPM are now working on developing a bench-top system to enable scientists worldwide to benefit from the advantages of iNTA. |
News
X Marks the Spot: AI’s Treasure Maps Lead to Early Disease Detection
Medical diagnostics expert, doctor’s assistant, and cartographer are all fair titles for an artificial intelligence model developed by researchers at the Beckman Institute for Advanced Science and Technology. Their new model accurately identifies tumors [...]
Scientists Discover Method To Identify Alzheimer’s Disease Before It Progresses to Dementia
Researchers at Aarhus University have discovered a method to identify Alzheimer’s disease before it progresses to dementia, potentially opening up new avenues for treatment. A groundbreaking study could pave the way for early detection [...]
Startling Discovery: COVID-19 Virus Can Stay in the Body More Than a Year After Infection
The COVID-19 virus can persist in the blood and tissue of patients for more than a year after the acute phase of the illness has ended, according to new research from UC San Francisco that offers potential [...]
New bioengineered protein design shows promise in fighting COVID-19
In the wake of the COVID-19 pandemic, scientists have been racing to develop effective treatments and preventatives against the virus. A recent scientific breakthrough has emerged from the work of researchers aiming to combat [...]
Sugar-coated gold nanoparticles can quickly eliminate bacterial infections, no antibiotics required
If left to their own devices, bacteria on our teeth or wounded skin can encase themselves in a slimy scaffolding, turning into what is called biofilm. These bacteria wreak havoc on our tissue and, [...]
Liquid Lightning: Nanotechnology Unlocks New Energy
EPFL researchers have discovered that nanoscale devices harnessing the hydroelectric effect can harvest electricity from the evaporation of fluids with higher ion concentrations than purified water, revealing a vast untapped energy potential. Evaporation is a natural [...]
Unmasking the Illusion: AI-Generated Faces Challenge Perceptions
Research shows survey participants duped by AI-generated images nearly 40 percent of the time. If you recently had trouble figuring out if an image of a person is real or generated through artificial intelligence [...]
New Discovery Reveals How Cells Defend Themselves During Stressful Situations
Stress granules play a crucial role in the stress response, arising from the aggregation of non-translating mRNAs and proteins. Although significant knowledge exists about stress granules, the mechanisms behind their mRNA localization remain partially [...]
Scientists use a new type of nanoparticle that can both deliver vaccines and act as an adjuvant
Many vaccines, including vaccines for hepatitis B and whooping cough, consist of fragments of viral or bacterial proteins. These vaccines often include other molecules called adjuvants, which help to boost the immune system's response [...]
Not Science Fiction: How Optical Neural Networks Are Revolutionizing AI
A novel architecture for optical neural networks utilizes wavefront shaping to precisely manipulate the travel of ultrashort pulses through multimode fibers, enabling nonlinear optical computation. Present-day artificial intelligence systems rely on billions of adjustable [...]
Turning skin cells into limb cells sets the stage for regenerative therapy
In a collaborative study, researchers from Kyushu University and Harvard Medical School have identified proteins that can turn or “reprogram” fibroblasts — the most commonly found cells in skin and connective tissue — into [...]
AI reveals prostate cancer is not just one disease
Artificial Intelligence has helped scientists reveal a new form of aggressive prostate cancer, which could revolutionise how the disease is diagnosed and treated in the future. A Cancer Research UK-funded study, published in Cell Genomics, has revealed [...]
New Study Finds That Persistent COVID-19 Infections Are Surprisingly Common
Recent research conducted by the University of Oxford has found that a high proportion of SARS-CoV-2 infections in the general population lead to persistent infections lasting a month or more. The findings have been published in the journal Nature. [...]
Innovative nanosheet method revolutionizes brain imaging for multi-scale and long-term studies
The human brain has billions of neurons. Working together, they enable higher-order brain functions such as cognition and complex behaviors. To study these higher-order brain functions, it is important to understand how neural activity [...]
Scientists Have Discovered a Potential Universal Antivenom
Scientists at Scripps Research identified antibodies that protect against a host of lethal snake venoms. Scripps Research scientists have developed an antibody that can block the effects of lethal toxins in the venoms of [...]
Scientists discover the human brain is even more powerful than we thought
The human brain could be far more powerful than we ever imagined, scientists have discovered. Researchers have identified cell messaging which have never been uncovered before, which suggests our brains are capable of more than previously realised. It’s [...]