A POLY(O-AMINOPHENOL) MODIFIED ELECTRODE AS AN AMPEROMETRIC HYDROGEN-PEROXIDE BIOSENSOR

An enzymatic biosensor for hydrogen peroxide based on a horseradish pe roxidase (HRP)-ferrocene carbon paste modified electrode and coated wi th a layer of electrochemically generated poly(o-aminophenol) is repor ted. A linear calibration curve is obtained over the range 1 x 10(-8) M to 1 x 10(-5) M. The biosensor responds to hydrogen peroxide ina few seconds and has a detection limit of 8.5 x 10(-9) M. The response of the biosensor is diffusion controlled at low substrate concentrations. Flow injection assays of hydrogen peroxide at a sampling rate of 150 injections per hour with a relative standard deviation of 0.8% (50 sam ples) are possible. Applicability of the sensor for measurement of hyd rogen peroxide in real samples (milk) was demonstrated. (C) 1998 Elsev ier Science Ltd. All rights reserved.