Multimodal Simultaneous Amperometry and Electrochemical Impedance Spectroscopy Measurement for Biosensing Applications

Electrochemical techniques are widely used for biosensing applications. Previous work has focused on the development of sensor readout circuits for any one of the electrochemical techniques. However, many sensors face the problem of sensor degradation, which can be estimated using sensor impedance. Amperometry for biosensing applications and impedance spectroscopy for study of sensor impedance can be utilized to study the impact of biofouling on sensor layers. In this paper, we have attempted to develop a sensor readout to concurrently perform amperometry and EIS simultaneously, thus simplifying the overall circuit. In this work, the circuit presented uses the sensing current derived from the Counter Electrode for sensing the impedance at the electrode-electrolyte interface. By mirroring the amperometric glucose sensing currenet concurrent impedance measurement is performed at DC without affecting the amperometric measurement of the sensor.