Environmental sensors and handheld devices able to detect and identify viruses would provide early warning of infections in individuals, the spread of disease in populations, and biological weapons attacks.

Harvard University researchers have built a detector from nanowires transistors that can identify individual virus particles in real time in unpurified samples. The prototype uses antibody proteins attached to the nanowires to briefly capture individual virus particles.

When an individual virus binds to a nanowire transistor’s antibody receptor, the transistor’s electrical conductance changes, increasing or decreasing depending on whether the transistor carries positive or negative charge and the virus is positively or negatively charged.

More in trnmag and PNAS.