An integrated potentiostat sensor with digitally-controlled input-parasitic compensation for nanopore applications

This paper presents an integrated low-power and low-noise potentiostat sensor for nanopore sensing. This high-sensitivity sensor consists of four stages: 1) a preamplifier, 2) a difference amplifier, 3) a unity-gain buffer and 4) a capacitive compensation unit. For the preamplifier, a resistive-feedback transimpedance amplifier with 50MΩ is used to detect an ionic current variation and the difference amplifier then provides a programmable voltage gain. The compensation block works to cancel out the input-parasitic capacitance effect, which causes a dead-time during nanopore sensing, as well as estimate it along with the control unit. For high-throughput nanopore sensing, in this work, a potentiostat sensor is designed and simulated in a 0.35μm CMOS process.