Half Bridge Operational Testing and Optimization for Chemiresistive Escherichia Coli Bacteria Sensor Application

Abstract

Balanced bridge circuits widely used in many electronics applications such as to measure changes in electrical magnitude, light intensity, pressure or strain. The wheatstone bridge is used in many applications for sensing a range of mechanical and electrical properties, but one that is very useful and critical in research area by using Wheatstone bridge is in the biosensor application. Many biosensors to detect harmful bacteria have been developed in the last few years, but the structure and application of the circuit operation still lacking in research publication. In this research, the simple circuit system was developed using half bridge operational with a stand-alone user interface. An Arduino microcontroller was used to operate the new device. The circuit was functionalized to detect resistance change with the help of Wheatstone bridge with half bridge operational principle for device calibration. The result shows that resistivity change that can be detected by the device was as low as 0.0426 Ω. Finally, by dropping the 1000 CFU/ml of E. coli bacteria sample in the sensing platform, the magnitude of change of 0.23 V was detected from the circuit reading with high stability obtained.