Studies on dynamic behavior of the biosensor based on immobilized glucoamylase glucose oxidase membrane

Frequency response of the glucose/maltose biosensors based on immobilized glucoamylase and glucose oxidase membranes of different thickness were investigated with the sinusoidal signal generator of substrate concentration. The results were modeled by the serial combination of the dead time and the first order response blocks, and time constants and dead times were estimated. The estimated value of time constant ranged from 4.5 to 13.2 s and that of the dead time from 3.2 to 7.7 s with the tendency that both time constant and dead time increase as membrane thickness increases and number of enzymatic reaction steps increases. (C) 1997 Elsevier Science Limited.