From research done at the University of Twente in the Netherlands:
Scientists of the Biophysical Engineering Group of the University of Twente in The Netherlands have developed an ultrasensitive sensor that can be used in a handheld device to, within minutes, detect various viruses and measure their concentration. The sensor could be used to quickly screen people at hospitals, airports and emergency clinics to control outbreaks of diseases such as SARS and the bird flu. All it would take is a tiny sample of saliva, blood, or other body fluid. Dr. Aurel Ymeti and others present their results in February’s issue of Nano Letters.
The essential innovation in the technique reported in this paper is the combining of an integrated optics interferometric sensor with antibody-antigen recognition approaches to yield a very sensitive, very rapid test for virus detection. The technology is amenable to miniaturization and mass-production, and thus has significant potential to be developed into a handheld, point-of-care device.
Here’s how the technology works (refer to the picture above):
Monochromatic light from a laser source is coupled to a channel waveguide and is guided into four parallel channels. These four channels include one reference channel (4) and three measuring channels (1-3) that are used to monitor different viruses by coating the channels with appropriate antibodies. Upon exiting from these four waveguide channels, the light interferes on a screen generating an interference pattern. Specific virus binding to the antibody coated waveguide surface causes a corresponding phase change that is measured as a change in the interference pattern. Analysis of the interference pattern thus yields information on the amount of bound virus particles on different channels.
The technique is better than traditional methods such as PCR (polymerase chain reaction) because of its speed and ease of use without compromising sensitivity. In principle, with a device such as this, minimal pre-processing of samples is required, and one could imagine having several different, interchangeable, detection modules for rapid detection. It’s also possible to consider configuring the device to detect multiple analytes.