Label-free optical biosensors for virus detection and characterization

Label-free optical biosensors have shown promise in rapid and sensitive detection of viruses. Recently, we have demonstrated a technique termed interferometric reflectance imaging sensor (IRIS) capable of detecting viral antigens and single viruses in a high-throughput, quantitative, and label-free fashion. In this paper, we briefly review the current label-free optical methods that have demonstrated virus detection through ensemble measurements of viral antigen and emerging techniques that are capable of detecting individual viruses captured by the sensor. We then present the principle of single nanoparticle detection using IRIS and show proof-of-principle results on specific detection and shape analysis of individual viruses captured on the IRIS platform.