CMOS potentiostat for chemical sensing applications

We demonstrate a CMOS (complementary metal oxide semiconductor) potentiostat chip fabricated in a standard 0.5 μm CMOS process to perform electrochemical analysis via cyclic voltammetry. This chip contains six independent channels for three electrode systems in electrochemical cells. Our low power circuit has been designed to drive electrochemical reactions in solution using class AB folded cascode amplifiers. The circuit operates with rail to rail input and output and has strong drive ability. We have shown the potentiostat chip is capable of performing cyclic voltammetry (CV) with both potassium ferricyanide and hexaammineruthenium chloride solutions. The chip is capable of differentiating both the composition and concentration of the solution. We compare our results with control experiments on a Gamry commercial electrochemical workstation and demonstrate they are consistent.