Purdue University researchers developed a miniature sensor, about the width of a micron, sensitive enough to detect a single virus particle. The device is a tiny cantilever, a diving-boardlike beam of silicon that naturally vibrates at a specific frequency. A virus particle, weighing about 1 trillionth as much as a grain of rice, landing on the cantilever causes it to vibrate at a different frequency, which is measured by Purdue researchers.
"The device lets us detect whole, intact virus particles in real time," says Amit Gupta, a doctoral student at Purdue. "Currently available biosensing systems for deadly agents require that the DNA first be extracted from the agents, and then it is the DNA that is detected," he adds. The next step will be to coat a cantilever with the antibodies for a specific virus, meaning only those particles would stick to it. The research is aimed at developing advanced sensors capable of detecting airborne viruses, bacteria, and other contaminants.