Whispering Gallery Detects and Sizes Smallest VirusContact: Janet Sassi
A rendering of the whispering gallery mode sensor.
Courtesy of Stephen Holler
A Fordham physics professor has collaborated with researchers at The Polytechnic Institute of New York University and City University of New York to detect the smallest known aqueous-borne virus through new nanotechnology.
Stephen Holler, Ph.D., and the researchers’ “plasmonic hybrid whispering gallery mode sensor” consists of a microscopic glass bead no wider than the thickness of a human hair (approximately 100 microns in diameter.) The bead has a single gold nanoscopic antenna affixed to its equator that, with the aid of light forces, draws a single virus particle to a nanoplasmonic “hot spot.” Using a wavelength tunable laser source, the team then interprets a signal obtained from the shifts in colors of light (i.e. resonances) that circumnavigate the glass bead, to detect and measure the size of the attracted particle--in this instance an RNA virus whose molecular weight is below that of all known viruses.
Such direct object detection of a single bio-nano-particle of this size had previously been unattainable, said Holler.
This record-setting achievement was published in the July 30 issue of Applied Physics Letters,
and subsequently highlighted by the American Institute of Physics
Holler said the new discovery has numerous useful applications for identifying and studying biological particles, but more importantly for real-time medical diagnostics.
“Having achieved a detection limit below all known virus particle sizes means that medical diagnostic technology may soon be capable of rapidly detecting the presence of a single virion in blood or saliva – including common viruses such as influenza, HIV, Hepatitis and West Nile," he said. "We envision doctors performing these tests in the office and getting results in minutes, not the days necessary for current blood tests. Early detection means immediate treatment, which can save lives.
“In addition, this sensor platform can serve as a sensitive device for monitoring for the presence of other biological and non-biological targets for medical (e.g., bacterial infection) and security applications (e.g., detection of biological or chemical warfare agents, explosives, and radiological/nuclear contamination).”
The researchers hope to soon push the detection limits further, and achieve single protein detection and characterization.
Founded in 1841, Fordham is the Jesuit University of New York, offering exceptional education distinguished by the Jesuit tradition to more than 15,100 students in its four undergraduate colleges and its six graduate and professional schools. It has residential campuses in the Bronx and Manhattan, a campus in West Harrison, N.Y., the Louis Calder Center Biological Field Station in Armonk, N.Y., and the London Centre at Heythrop College in the United Kingdom.