Design and simulation of impedance measurement system for biosensors

According to the requirement of the measuring impedance changes of biosensor caused by the specific binding of antibody and antigen, we designed an impedance measurement system for the biosensor which is able to work well within the range of frequency between 20Hz-100MHz. Besides of this, fast measurement, high accuracy, small size, and simple calibration are also needed. In this paper, the principle of impedance measurement and the circuit design methods were discussed, also the schematic diagrams of the system was showed. Finally the system was simulated by Multisim10 software. The results showed that the system could meet the need to measure impedance parameters within the wide frequency band with some satisfactory accuracy. Lay a good foundation for made of the test system and for the research of impedance data processing for the biosensor.