Breakthrough in biosensing: New virus detection method under development

Their work has made it possible, for the first time, to detect the smallest virus particle. Since even one viral particle can represent a deadly threat, the research likely will make an important contribution to ongoing research on early detection of such diseases as AIDS and cancer.

Until the research team announced their discovery this year in Applied Physics Letters (July 27, 2012, American Institute of Physics), no instrument or methodology had been successful in reliably and accurately detecting a single virus particle, which is in the size range of a nanoparticle. (About 80,000 nanoparticles side by side would have the same width as a human hair.)

The research will potentially have an immense impact on the general public, aiding disease detection at its earliest stage when fewer pathogens are present and medical intervention can be most effective. This new approach also has possible applications in the identification of numerous molecules, especially proteins, which are important for drug development research, both as the targets and the treatments.

While scientists have long used microscopes to view objects as small as bacteria, viruses are much smaller. Even the most sensitive electron microscopes, which are cumbersome, expensive and difficult to operate, cannot guarantee detection of these tiny particles. The team's breakthrough involved adding a nano-antenna to the light-sensing device to enhance the signal. "The idea that light can 'sense' the presence of nanoparticles and respond to their arrival was groundbreaking," Dr. Kolchenko says.

"Since all the deadliest viruses and most interesting biological molecules -- proteins and DNA -- belong to the nano world, our research proved truly innovative, and its promise is almost unlimited in terms of detecting pretty much everything of interest in life sciences," he adds.

Dr. Kolchenko, who has a medical degree, a doctorate in physiology and a master's degree in mathematics from Kiev University, provided a unique combination of expertise in bioinformatics, mathematics and medicine that was integral to the project's success in isolating the smallest individual RNA virus, MS2.

"I first became interested in pursuing research on using light for the detection and measurement of the tiniest biological and non-living objects when I heard a talk on biosensors that Professor Stephen Arnold of Polytechnic/NYU gave at City Tech," says Dr. Kolchenko, who teaches biology at City Tech and bioinformatics at Polytechnic.

The two-year research project, funded for $400,000 by the National Science Foundation, has been conducted at Polytechnic/NYU's Micro-Particle Laboratory for BioPhotonics, under the direction of Dr. Stephen Arnold, in collaboration with the physics departments of Fordham University and Hunter College, and the biological sciences department of City Tech. Polytechnic/NYU has applied for a utility patent for the team's ground-breaking innovation.

Prior to the latest NSF project, ten years of laboratory research by Dr. Kolchenko and his colleagues resulted in the development of a simple, low-cost design for more sensitive, miniature devices that could detect and measure viruses, proteins and DNA in real time. From 2005 through 2008, the team published papers detailing its progress in such journals as Applied Physics Letters, Faraday Discussions and Proceedings of the National Academy of Sciences.

"One of the ultimate goals is to develop portable, inexpensive, easy to use and highly sensitive devices for healthcare and research settings," says Dr. Kolchenko. "This research opens the door for highly sensitive detection and measurement of biological and other nanoparticles that are essential in molecular biology, clinical medicine and diagnostics, epidemiology, ecology, nanotechnology and other fields."

Further research is planned, according to Dr. Kolchenko. "Since single protein molecules are much smaller than viral particles, their detection will be the ultimate test of the method," he says. "We hope after some additional research and development, our method will allow for single protein detection as well."

Such research could enable the earlier screening of cancer markers, which are protein molecules produced when cancer grows. Currently, there are several markers that could be potentially detected by the new biosensor; early detection of these markers could allow treatment to begin sooner, enhancing cancer survival rates.

Says Dr. Kolchenko, "We have merely scratched the surface of what is likely to be possible."

New York City College of Technology (City Tech) of The City University of New York (CUNY) is the largest public college of technology in New York State. Located at 300 Jay Street in Downtown Brooklyn, the College enrolls more than 16,000 students in 63 baccalaureate, associate and specialized certificate programs.