Design of a voltammetry potentiostat for biochemical sensors

In this paper, we design a voltammetry potentiostat chip for the signal processing of electrochemical biosensors. Based on the sigma-delta modulator approach, the measured sensor current can be converted directly to the number of digital pulse. The measured results can be digitized by a simple counter without using a high resolution ADC. The proposed potentiostat is implemented by 0.35 mu m CMOS technology, and the chip layout area is 1 mm(2). In the proposed potentiostat, the maximum range of the measured sensor current is 12 mu A under the resolution of 10 nA. In system verification, the proposed potentiostat chip is successfully applied in the signal processing of an electrochemical creatinine biosensor. In the further applications, the potentiostat can be integrated with microelectrodes of biosensors on a small chip area to reduce the cost.