Differential Structure Solid-State Array Biosensors for Creatinine Detection

This work presents a differential structure of solid-state creatinine array biosensor based on an ion-selective membrane. The creatinine enzyme is chemically immobilized by a physical immobilization method onto an ammonium ion-selective membrane. Moreover, the solid-state creatinine biosensors based on ammonium ion-selective membrane respond rapidly, stably and linearly in the range of creatinine concentrations between 15μM and 140 μM. An array sensing system is designed to enhance the precision of the solid-state creatinine biosensor, which comprises four parts, the creatinine biosensors, the input buffer circuit, the differential circuit and the weighted sum circuit. As indicated in the experimental results of the array sensing structure, the sensing characteristic of the array sensing structure is similar to the mean sensing characteristic from four solid-state creatinine biosensors.