How tiny? They’re measured in nanometers, which is one-billionth of a meter. Like the width of a marble compared to the width of the Earth.

By going that small, Koenigsmann and his students have innovated in the areas of biomedical sensors and sustainable energy technology. Now his lab has a new project: scrubbing the air clean of viruses like the one that causes COVID-19.

Preventing Cases of COVID-19

Koenigsmann sees a way to improve on a type of indoor air purifier—activated by ultraviolet light—that destroys particles of coronavirus and other viruses but can also create tiny amounts of toxic byproducts under certain conditions.

Such devices have been around for decades, and were used in hospitals to remove tuberculosis from the air, “so it’s a proven technology,” said Koenigsmann, an associate professor in the chemistry department. “It’s just [that] as it becomes scaled up and more broadly used, and in environments where the air is not tested as regularly, that’s where you can run into problems.”

He and his team are working on new technology that could break down viruses without releasing toxins, which could lead to new types of purifiers that destroy viruses on a greater scale. On a recent summer day, in a lab at the Rose Hill campus, they were getting ready to run experiments using ductwork and a filter containing new types of nanoparticles.

The lab also includes a high-temperature reaction chamber and other tech for making the nanoparticles themselves—indispensable because they’re so small.

Surface Appeal

Koenigsmann, an associate professor in the chemistry department, has long been fascinated with “being able to tune fundamental physical properties” of a substance by changing its size or other aspects.

Break a substance down into smaller units, he explains, and suddenly it’s a lot better at reacting with things, since a lot of small particles will have more total surface area than a few large ones.

How much more? If you’re turning something into nanoparticles, one square meter per gram could become hundreds of square meters per gram. “For the same amount of mass, you gain a tremendous amount of surface area,” he said.

And more surface area means more reactions. For instance, a battery made from nanoparticles offers vastly more internal surface area for conducting an electric current. And air purifiers operating on the same principle offer more surface area for reacting with viruses and churning them up.

Filtering Coronavirus

In some of today’s air purifiers, Koenigsmann said, titanium dioxide chews up a virus particle in a chemical reaction that yields carbon dioxide when it runs its course—but formaldehyde, carbon monoxide, or other toxins when it doesn’t.

To address this problem, Koenigsmann and his team are working on new types of nanomaterials that, because of their size and composition, will fully break down virus particles, giving off only carbon dioxide and opening the door to purifiers that are safe to use more widely.

His undergraduate students contribute a lot to the project—“They’ll tell you things that you wouldn’t have thought of yourself,” he said. “I’m actually learning as my students learn.”

The uses for nanotech seem endless, Koenigsmann said. “The ability to tune things like conductivity, color, catalytic activity, just by making the same material one shape or one size versus another [has] so many possible applications,” he said.

Working with chemistry professor Ipsita Banerjee, PhD, Fordham undergraduates are learning how 3D printers can be used to make replacement organs for people afflicted with osteoarthritis, cancer, or other conditions.

Along the way, they’re also learning what it’s like to be a research scientist: the long hours in the lab, the painstaking analysis, the late nights spent poring over data—and the joys of digging into fascinating scientific questions.

“I wouldn’t look at it as necessarily work,” said biology major Steve Romanelli.

That’s a typical outlook among students who work with Banerjee, whose one-on-one attention and high expectations often propel students into careers of scientific inquiry.

“Basically, I train them as scientists” by offering graduate-level tutelage, which leads many of them to fall in love with research and pursue it at universities like Oxford, Cambridge, and UCLA upon graduating, she said.

It helps, of course, to have engrossing subjects to explore. People have used 3D printing to turn three-dimensional digital images into all kinds of objects, ranging from food to firearms, and according to Banerjee it’s revolutionizing the field of tissue regeneration.

Instead of examining cells two-dimensionally, under glass on a microscope, scientists can use 3D printers to create tiny models, or scaffolds, in the shape of an organ. By filling these scaffolds with cells, they get a clearer idea of how the cells function when they’re bunched together in the organ itself.

This knowledge can then be used to fashion small replicas of organs and tissues that, when implanted, grow to their full size naturally, just as the original ones did, Banerjee said. The patient’s own cells can be used so the body’s immune system isn’t triggered, and the scaffold biodegrades as the organ grows.

But more research is needed before this technique can be used widely, and inexpensively, with minimal side effects, Banerjee said.

Her team concentrates on regenerating bone tissue and cartilage, but also skin tissue and the cornea. Banerjee’s students work on synthesizing the scaffolds and making sure they have the right properties.

Made from proteins, minerals, collagen, or other materials, depending on the type of organ being studied, the scaffolds have to be precisely designed at the nanoscale. If the composition isn’t right they might disintegrate too quickly, soak up water, attract bacteria, or trip the body’s immune defenses.

Getting the shape right is also important, especially for a cornea scaffold, which has to have the correct refractive index. Also, of course, it has to be transparent.

“That’s a very interesting challenge, but it’s fun also,” Banerjee said. “All of these are equally challenging, but each one has its own nuances that you can work with.”

Over the years, many of Banerjee’s students—Romanelli included—have been published in professional journals and presented their research at professional conferences, where they’re often the only undergraduates on the program. Their conference presentations have won several awards.

Banerjee has seen many pre-med students change their plans and pursue research instead after learning what it’s like. Romanelli, for instance, wanted to be an orthopedic surgeon when he started working with Banerjee in his sophomore year. But now, as he prepares to begin senior year, he hopes to eventually earn a doctorate in biomedical engineering instead.

Coming to the lab is “kind of a stress relief, almost,” he said. In Banerjee’s words, “It becomes a part of who you are, after a point.  With them, it’s like, ‘This is what we do.’”