A Mediator-free Horseradish Peroxidase Biosensor Based on Concanavalin A

A media-free horseradish peroxidase (HRP) biosensor has been developed. First, HRP was adsorbed by gold nanoparticles and then immobilized on the bare gold electrode surface by activated concanavalin A (Con A). The factors influencing the performance of the resulting biosensor were studied in detail. The optimum conditions were pH 7.0 and an applied potential of −150 mV. The electrode provided a linear response to H2O2 over a concentration range of 5.0×10−6 to 1.2×10−2 M with a detection limit of 2.9×10−6 M. The system was applied for the determination of the samples, and the results obtained were satisfactory.