Bi-functional amperometric biosensor for low concentration hydrogen peroxide measurements using polypyrrole immobilizing matrix

Usage of nanoporous polypyrrole on H2O2 bi-functional sensing after immobilizing horseradish peroxidase (HRP) is described in this paper. Nanoporous alumina membranes were used to produce nanopores on polypyrrole surface. Nanopores increased the effective surface area available for enzyme immobilizing. Further, this increased area enhances the electron flow caused by the catalytic reactions. When the sensor was deployed to sense H2O2 at 0.2 V a high sensitivity of 3.9 A M−1 cm−2 was observed at a fast response time of 5 s. When the working potential was reversed to −0.1 V, a wider linear range of 10 nM to 25 μM was achieved. These novel findings will lead the way to a new path of biosensor design for low substrate concentrations with enhanced characteristics.