Sensor system for simultaneous measurement of oxygen and hydrogen peroxideconcentration during glucose oxidase activity

An amperometric sensor system, based on a repetitive double step potential method at a glassy carbon electrode, has been developed for the simultaneou s measurement of hydrogen peroxide and oxygen concentrations. The current m easured at a potential of -1V (vs. Ag/AgCl/saturated Cl-) corresponds to th e sum of the reduction currents of hydrogen peroxide and dissolved oxygen. The current measured at -0.55 V (vs. Ag/AgCI/saturated Cl-) is due to the r eduction of dissolved oxygen to hydrogen peroxide. Alternatively, the conce ntration of dissolved oxygen can also be determined using a Clark electrode . The concentration of hydrogen peroxide and dissolved oxygen during enzymati c conversion of glucose can be followed an line and be used to control the process.