A Review of Electrochemical Electrodes and Readout Interface Designs for Biosensors

Electrochemical detection is widely used in biosensing fields, such as medical diagnosis and health monitoring due to its real-time response and high accuracy. Both passive and active electrodes and the corresponding readout circuits have been continuously improved over the past decades. This article summarizes the redox reaction method, state-of-the-art electrode materials, and readout circuits based on the passive three-electrode. The redox-current-based readout circuits are widely used and developed toward multichannel high precision and low power consumption. In terms of active electrodes, this article reviews the development of field-effect transistors (FETs)-based electrochemical detection and readout circuits. In the past decade, the development of organic electrochemical transistors (OECTs) has also enabled more precise electrochemical detection.