Concanavalin A as carrier for sensitive electrochemical immunosensor based on AgNPs-rGO signal amplification

Concanavalin A (ConA), as a carrier for immobilizing antibodies, was used for the first time in electrochemical immunosensor. In this work, a label-free electrochemical immunosensor based on Ag nanoparticles-reduced graphene oxide (AgNPs-rGO) nanocomposite and ConA was successfully prepared to detect arsanilic acid (ASA). AgNPs-rGO nanocomposite displayed superior conductivity and redox capability. Specially, ConA showed excellent binding ability with monoclonal antibody of ASA through lectin-sugar interactions. Under the optimized conditions, the proposed electrochemical immunosensor showed a linear dependence over ASA concentrations ranging from 0.025 ng/mL to 25 ng/mL with a low detection limit of 0.011 ng/mL. Furthermore, the immunosensor was used to monitor ASA in chicken and egg with good precision and accuracy. In conclusion, the simple and low-cost immunosensor was desirably applied as a useful candidate for detection of ASA in animal derived food.