Hemagglutinin gene based biosensor for early detection of swine flu (H1N1) infection in human

Hemagglutinin (HA) is a glycoprotein found on the surface of influenza A subtype virus H1N1 which play a major role in infection to the human by binding the virus to cells with sialic acid on the membrane of upper respiratory tract or erythrocytes. Based on sequence of HA gene an impedimetric biosensor was developed by immobilizing amino labeled single stranded DNA probe onto cysteine modified gold surface of the screen printed electrode for early and rapid detection of H1N1 (Swine flu) in human. The electrochemical impedance was recorded after hybridization of probe with single stranded cDNA (ss-cDNA) of H1N1 patient samples in presence of redox couple. All available methods for detection of H1N1 including RT-PCR are either expensive or time consuming. However, impedimetric biosensor is not only highly specific for H1N1 virus but also can detect as low as 0.004 ng (limit of detection) ss-cDNA in 6 µL only in 30 min. The sensitivity of the sensor was 3750 Ω cm^-2 ng^-1 of DNA. The biosensor was well characterized using surface cyclic voltammetry, validated with patient samples and compared with existing methods. The sensor can be used in hospitals, diagnostic centres as well as in remote areas for early and rapid diagnosis.