Chemical sensor systems using xerogels and CMOS detectors

We have developed a chemical sensing platform based on xerogel thin film sensor elements coupled with CMOS detectors. We demonstrate the operation of the sensing platform as a simple oxygen sensor. The quenchometric operation of the oxygen sensor coupled with CMOS detectors is compared to standard laboratory detection systems (CCD and PMT). The Stern-Volmer quenching constant (k_SV) is used as a comparative measure of the operation of each of these systems. In our initial experiments all three systems yielded a k_SV between 0.042 and 0.049 O₂%^-1. The xerogel sensor elements have demonstrated satisfactory reusability and stability over a period of more than six months. The CMOS detectors consume less than 0.1% of the power required for the PMT or CCD detectors, and are an attractive platform for array processing and portable applications.