A Fully Integrated CMOS Sensor for Pico-current Measurement on Solid-state Nanopore Devices

Abstract

In this paper, an integrated high-sensitivity patch-clamp sensor is proposed to measure the ultra-low current variation of a solid-state nanopore device. This sensor amplifier consists of three stages: 1) a headstage, 2) a difference amplifier and 3) a unity-gain buffer. For the headstage, a resistive-feedback transimpedance amplifier is employed to convert the small current to a readable voltage. The addition of a programmable gain to the second-stage difference amplifier allows the maximum gain to be increased to 168dBΩ. This sensor is fabricated in a 0.35μm CMOS process and is tested with an 80nm-diameter solid-state nanopore. We present a detailed circuit analysis for the low-noise patch-clamp design and its noise measurement result in this paper.