Low-noise single-chip potentiostat for nano-bio-electrochemistry over a 1MHz bandwidth

A single-chip versatile potentiostat is presented that allows multiple amperometric electrochemical measurements at the nanoscale. Cyclic voltammetry, impedance spectroscopy, impedance time tracking and amperometry can be performed over a 1MHz bandwidth, with sub-pA resolution and over an unlimited measuring time. The design of the current amplifier, based on a simple transistor matching architecture, is illustrated. The results of the experimental characterization and of the validation electrochemical tests are discussed. The performances demonstrated, such as 3aFrms capacitance resolution with an applied 100kHz sinusoid of only 25mV, are suitable for electrochemical investigation at sub-micrometric electrodes, in particular for biotechnology applications.