The researchers are also able to detect the virus in human serum, or blood plasma. This is typically harder to do than detecting the virus in a saline solution because serum contains many different proteins that can attach to the antibody and cause errors. So far, the sensor only detects the virus if its concentration in serum is high. To be useful, the improved prototype sensor should be able to accurately measure low concentrations in different body fluids.

While the sensor has only worked for the herpes virus, the researchers hope to soon demonstrate it for other viruses in order to make it widely applicable. To detect the SARS, HIV, or bird-flu virus, the researchers would have to attach antibodies specific to those viruses on the light channel. By attaching different antibodies on different light channels, the same sensor could detect multiple diseases.

Detecting various viruses with this device shouldn't be a major hurdle, says David Gottfried, a biosensor researcher at the Georgia Tech Research Institute. Until now, no one has demonstrated a fast, portable sensor that can be used to detect viral diseases on-site. "This is one of the first demonstrations of a biosensor technique that could be [practical] for viruses, and it has the sensitivity required for early detection," Gottfried says.

Ymeti says that the goal is to have a small microfluidics device that can test for different diseases simultaneously. He expects such a prototype to be ready within the next two years.