Use of a Low-Cost CMOS Detector and Cross-Polarization Signal Isolation for Oxygen Sensing

A portable, low-cost optical oxygen sensor based on quenching of PtOEP emission is described. A CMOS image sensor was used as detector, while cross-polarization was used for signal isolation. At high oxygen concentrations, emission of PtOEP was quenched leading to changes in the red channel of the CMOS sensor, while the green and blue channels exhibited little signal change. Sensitivity of the integrated sensor was comparable to that of commercial sensors utilizing bulky and expensive external optical components. The wide dynamic range of the demonstrated approach will permit use in a large variety of point-of-care oxygen-sensing applications.