Scanning electrochemical microscopy inside the biocatalytic layer of biosensors, investigation of a double function complex multienzyme reaction layer

As the continuation of the work started earlier, this article deals with the scanning electrochemical microscopic (SECM) study of the function of complex enzyme sensors. In this case reaction layer of the sensor is made of two different parts. One is for interference elimination and the other for selective molecular recognition and measurement. As Scheller's group described this sucrose electrode, the inner that is the measuring layer contains three enzymes: invertase, mutarotase and glucose oxidase while the outer, the eliminating one, uses glucose oxidase and catalase. In our work the concentration profiles of oxygen and hydrogen peroxide were recorded inside the two different enzyme layers with the SECM. The dependence of these profiles on the working parameters such as enzyme activity and activity ratios, reaction layer thickness, sucrose and glucose concentration were observed and compared with the results of model calculations. Method of finite differences was used for the model calculations.