Nanoscale transistors made from silicon nanowires can detect a bacterial toxin responsible for the most common form of food poisoning, claim US scientists.

The toxin forms a complex with the antibody coating on the surface of the transistor

Nirankar Mishra and his team at the University of Idaho used nanolithography, a process that patterns nanometre-sized structures, to make silicon nanowires. They connected the ends of the wires to gold terminals to form a transistor. By coating the surface of the transistor with an antibody, the team were able to detect the toxin Staphylococcus aureus Enterotoxin B (SEB), which formed a complex with the antibody and altered the electric current through the transistor.

Mishra says he hopes that the transistors, known as field effect transistors, will one day be integrated into hand-held electronic devices for detecting different types of toxins. 'Research into nanodevices has enormous potential in the diagnostics world,' he says. 'Using field effect transistors for biodetection could enable highly sensitive and cost-effective devices to be produced.'

Katherine Davies