A new silicon chip that harnesses emerging technology at the nano scale will allow the detection of viruses faster, and more accurately, than ever before. One of the applications of this new technique will help save thousands of lives in patients undergoing heart transplants; by enabling doctors to detect rapidly whether a donor heart is infected or not. The scientists announced their discovery today in the Institute of Physics journal Nanotechnology.
The device, called the “ViriChip” was developed by a team led by Dr Saju Nettikadan from BioForce Nanosciences, in collaboration with Des Moines University, both in the USA.
The ViriChip is a small silicon chip about a quarter of an inch across (6mm) which has tiny droplets of antibodies printed on the surface. A single ViriChip can be printed with hundreds of different antibodies. These antibodies act as landing pads for viruses, which attach themselves selectively to certain antibodies. Once the viruses have landed on a particular droplet, they can be detected using an atomic force microscope (AFM). The AFM is a small and simple machine that uses a tiny “finger” to feel bumps on the surface of the chip at the nanometer scale. The AFM method is fast, very sensitive (it can “see” individual viruses) and it does not destroy the viruses so they can be further analyzed e.g. by cell culture and other methods.
Nettikadan’s team showed that this technique worked by detecting six different strains of a virus called coxsackievirus B. Coxsackievirus B causes symptoms ranging from mild cold to death, and is one of the key factors causing the failure of heart transplants. The ability to detect coxsackievirus B could save thousands of lives by allowing a physician rapidly to determine if a donor heart is infected.
Dr Eric Henderson, founder and Chief Scientist at BioForce Nanosciences said: “This is the first time scientists have been able to routinely apply droplets of an antibody on the micron to nanometer scale to a surface of a material like a silicon chip. In principle you can fit thousands of different antibodies on one chip and use it to test for thousands of different viral infections simultaneously, using just one sample from a patient. This means patients won’t have to provide large blood samples, just a single drop will be sufficient. It also means the results will come back in record time and further studies can be carried out on the unperturbed sample using more conventional, if slower, methods. The technique is currently being used by researchers and we hope it will be available for doctors and hospital pathology labs in the next two years.”
