Rapid flu diagnosis using silicon nanowire sensor.

Influenza epidemics worldwide result in substantial economic and human costs annually. However, rapid and reliable flu diagnosis methods are significantly lacking. Here we have demonstrated the selective detection of influenza A viruses down to 29 viruses/μL in clinical exhaled breath condensate (EBC) samples (diluted by 100-fold) within minutes using silicon nanowire (SiNW) sensor devices. For 90% of the cases, we have observed that EBC samples tested positive or negative by gold standard method RT-qPCR generated corresponding positive or negative SiNW sensor responses. High selectivity of SiNW sensing was also demonstrated using H1N1 viruses, 8 iso PGF 2a, and inert nanoparticles. Finally, magnetic beads were shown capable of enhancing SiNW sensing directly for low level viruses and 8 iso PGF 2a. When calibrated by virus standards and EBC controls, our work suggests that the SiNW sensor device can be reliably applied to the diagnosis of flu in a clinical setting with 2 orders of magnitude less time compared to the gold standard method RT-qPCR.