Bacteria growth monitoring through an on-chip capacitive sensor

In this paper, a charge based capacitive biosensor is presented for bacteria growth monitoring (BGM). This sensor chip is implemented through CMOS process in order to show the applicability of the proposed on-chip capacitive technique for BGM purposes. The passivated interdigitated electrodes atop CMOS chip are exposed to Escherichia coli (Ecoli) bacteria in the channel. The presence of bacteria in proximity of electrode causes a minute change in double layer capacitance. The variation of this capacitance (DeltaC<60 pF) versus time is demonstrated and compared with conventional impedance-based technique.