Researchers find way to make the smallest nanoparticles visible

Use of a new optical technology will now help scientists to see some of the smallest nanoparticles, measured at 25 nanometers in diameter

Researchers have created a new optical imaging technology for nanoscale objects, using unscattered light to detect nanoparticles as small as 25 nanometers in diameter.

The technology is called PANORAMA. It uses a glass slide covered with gold nanodiscs, allowing scientists to monitor changes in the transmission of light and determine the target’s characteristics.

Why are nanoparticles important?

They are fighting COVID-19

Aarthi Janakiraman, Research Manager, Chemicals and Advanced Materials at TechVision, Frost & Sullivan, writing on the value of nanotechnology, said: “Touted as one of the game-changing technologies of the century, nanotechnology has the potential to aid in developing solutions that can help in the prevention, diagnosis and treatment of COVID-19.

“Metal nanoparticles (NP), especially silver (Ag) and gold (Au) are used in various disinfection solutions.”

They could also fight lung cancer

Darcy Wagner, Associate Professor and Head of the Lund research group, commented: “While smart nanoparticles with unique features can be engineered in various ways, systemic administration of these agents into the bloodstream often results in uncontrolled spread of the particles with only a few of them reaching the interior of solid tumours.

“This has been a global challenge hampering more wide-spread use of nanoparticle systems in the clinics.”

Essentially, nanoparticles could give oncologists the precision to destroy only the tumour – not the living tissue of the lung.

They are fighting food insecurity

Wade Elmer of The Connecticut Agricultural Experiment Station, commented: “Nanoparticles of metallic oxides (<100 nm) have great potential as fertilisers and as tools to increase plant health. We have found that nanoparticles of metallic oxides of the plant micronutrients Cu, Mn, and Zn tend to have positive effects on plant health and perform better than their larger bulked or chelated equivalents.

“Surprisingly, we observed that when nanoparticles of these metallic oxides were sprayed onto the leaves of plants that were infected with root pathogens, they did better than their untreated controls.

For plants, some soil-borne diseases are hard to manage. With the increasingly turbulent climate, plants are not just decorations for offices – they are the only available nutrition. Growing food is infinitely easier when the diseases that attack plants can be wiped out with satisfying precision.

The research behind the new technology to see nanoparticles

Scientists from the University of Houston and the University of Texas M.D. Anderson Cancer Center worked together to create and use PANORAMA to handle the small nanoparticles.

Wei-Chuan Shih, professor of electrical and computer engineering at UH and corresponding author for the paper, said:

“The smallest transparent object a standard microscope can image is between 100 nanometers and 200 nanometers. That’s mainly because – in addition to being so small – they don’t reflect, absorb or “scatter” enough light, which could allow imaging systems to detect their presence.

What is labelling in nanotechnology?

Labelling is another commonly used technique; it requires researchers to know something about the particle they are studying – that a virus has a spike protein, for example – and engineer a way to tag that feature with fluorescent dye or some other method in order to more easily detect the particle.

But sadly, labelling is only useful if researchers already know at least something about the particle they want to study. So the use of PANORAMA will change the game, as researchers will not need to know anything about the particle they’re looking at, to see it. This is the difference between scattered and unscattered light.

Think of it as if you want to access someone’s email account, you need a password. This is a passworldless world now for nanoparticle researchers.

Read the full study here.