BioCMOS LSIs for portable gene-based diagnostic inspection system

Monolithically integrated sensor arrays are described for potentiometric, amperometric, and impedimetric sensing of biomolecules. For the potentiometric sensor array, a new high-density, low-power source-drain follower was developed. Fabricated 16×16 sensor array demonstrates pH, DNA, and redox reaction detections as statistical distribution observing time and space fluctuations. For amperometric sensor array, we proposed a switching circuit and an electrode design for measuring multiple microelectrode currents at high speed. Each electrode has a steady-state current, which is amplified by a redox cycle, and the time to reach the steady state is reduced to about 1/10 of that required by a single microelectrode. For the capacitance sensor array, charge-based capacitance measurement (CBCM) is used. A 20% change in capacitance (10 fF) before and after the injection of complimentary target oligonucleotides is successfully observed. Multimodal sensor array with potentiometric, amperometric, and impedimetric sensor units will offer general purpose biosensor chip for portable gene-based diagnostic inspection system.