A tunable CMOS read-out integrated circuit for carbon nanotube-based bio-sensors

A robust and tunable read-out integrated circuit architecture is presented for carbon nanotube-based bio-sensor with nano-amperes current measurement at 1ms to 16 minutes intervals. The circuit contains an on-chip 8-bit analog-to-digital convertor and a trans-impedance amplifier with tunable control parameters to accommodate not easily controlled single-walled nanotube sensor fabrication with a wide distribution of resistance ranges. For one of the prepared carbon nanotube devices, the current estimation accuracy is within 0.38 nA for a carbon nanotube sensor with expected effective resistance range between 5-30 MΩ This corresponds to current measurements between 5-45 nA. This CMOS instrumentation core has an approximate area of 639 μm² and consumes 33 mW at 5 MHz sampling rate.