An Integrated Potentiostat With an Electrochemical Cell Using Thin-Film Transistors

We developed an integrated potentiostat with an electrochemical cell using thin-film transistors (TFTs). The integrated potentiostat consisted of three operational amplifiers composed of poly-Si TFTs, whereas the electrochemical cell was fabricated using a printing technology. These microsensor components were integrated on a glass wafer to assemble a micrototal analysis system. A cyclic-voltammetry measurement was performed as a standard biosensing experiment to confirm the elementary function of the integrated potentiostat. The expected characteristic was acquired by an amperometric enzymatic redox reaction using glucose oxidase and ferrocene mediators, and a glucose concentration of as low as 0.7 mM was detected, which is sufficient sensitivity for some medical applications including diabetic diagnosis.