Researchers show method to detect single viruses, nanoparticles in real time

Two researchers at the Institute of Optics at the University of Rochester in New York have developed a method to detect and recognize single viruses and other nanoparticles in one millisecond. A key aspect of the method is using interferometric detection. The interferometrical process combines two laser beams which are related to each other to make an interferometric pattern. A beamsplitter divided a 532nm laser beam into a reference beam and a beam which scientists focus into a nanoscale channel. The scientists then put a particle solution through this channel with electroosmosis.

Electroosmosis is liquid movement using electrodes. The process is rather straightforward: The scientist dips a positive electrode on one side of a glass tube and a negative electrode on the other and apply voltage. The amount of voltage determines how fast a particle moves inside the tube. Only one particle at a time crosses the laser focus because of the channel’s dimensions and the focus size. The laser causes the particle to brighten. “The extent of brightness of the nanoparticle depends on the particle’s properties, such as size and amount of transparency,” says Fillip Ignatovich, one of the researchers.

-read more on this fascinating new method in PhysOrg report