A CMOS Bio-Chip combining pH Sensing, Temperature Regulation and Electric Field Generation for DNA Detection and Manipulation

We present a novel System-on-Chip (SoC) design for DNA amplification and detection with the ability to electrostatically manipulate DNA molecules. The chip integrates an array of ISFET sensors for pH monitoring with heaters for temperature regulation, which enables amplification methods requiring thermal cycling or constant temperature. The sensing array comprises 1129 pixels, with each pixel based on an ISFET front-end with a programmable gate and implemented in a unity gain buffer configuration. The pH readout achieves a sensitivity of 196.5mV/pH with a gain of 30 and a frame rate of 80.5 fps. A temperature characterisation demonstrates that the system is capable of raising the temperature of a 10μL chemical solution to 96.44° C. Lastly, the on-chip interdigitated electrodes use a dielectrophoresis (DEP) technique to generate an AC sinusoidal electric field over a frequency range of 100Hz-1MHz with a simulated amplitude of approximately 100kVm^-1 to orient and immobilise DNA molecules at the ISFET sensing interface.