The detection of papaya ringspot virus coat protein using an electrochemical immunosensor

Abstract

Papaya is a widely grown and economically important fruit crop in the tropics and subtropics. A serious threat to papaya cultivation is a highly destructive disease caused by papaya ringspot virus (PRSV) which can result in complete loss of yield. Early identification and removal of PRSV infected plants can prevent the spread of the disease throughout the orchard and avoid significant crop loss. In this study, an electrochemical impedance spectroscopy-based immuno-sensor was developed for the highly sensitive detection of PRSV coat protein (PRSV-CP). The PRSV-CP gene was cloned and recombinant protein was expressed and purified from E. coli. Polyclonal antibodies were raised against the recombinant PRSV-CP, and their specificity as well as reactivity was assessed by western blotting and ELISA using extracts from healthy and PRSV-infected papaya plant saps. The electrochemical sensor surface was functionalized with the anti-PRSV-CP antibody to demonstrate the highly sensitive detection of the PRSV-CP. A prototype of the biosensor has been developed that provides a convenient on/off visual signal to rapidly identify papaya samples that contain the PRSV-CP. The technology developed in this study has the potential to serve as a rapid, easy-to-use, economical tool for the detection of plant pathogens in the field.