Scalable biosensors using standard CMOS process

In this study, we present two biosensors, an Ion-Sensitive Field-Effect Transistor (ISFET) and a Capacitance sensor array, both fabricated via a standard 0.5µm CMOS process. The integrated ISFET was comprehensively characterized and measured in a buffer solution across three pH variants (4, 7, and 10), revealing an impressive sensitivity of 35mV per pH unit for our CMOS-based ISFET. To counteract the prevalent issues of drift and mismatch, we have discussed applicable strategies to mitigate them. We utilize the ISFETs to monitor breast cancer cell growth showcasing their use for biomedical application. Moreover, we have introduced a fringe-based capacitance sensor array equipped with readout circuits, which measures the capacitive coupling of cells, thereby facilitating real-time monitoring of cells with high spatial and temporal resolution. Both the ISFET and the capacitance array are integrated on a CMOS substrate, opening avenues for large-scale biosensor integration.