Nafion film/K(+)-exchanged glass optical waveguide sensor for BTX detection.

An optical waveguide (OWG) sensor for the detection of BTX gases is reported. The highly sensitive element of this sensor was made by coating the copper Nafion film over a single-mode potassium ion exchanged glass OWG. We used the OWG sensor to detect toluene gas as a typical example BTX gas. The sensor exhibits a linear response to toluene in the range of 0.25-4250 ppm with response and recovery times less than 25 s. The sensor has a short response time, high sensitivity, and good reversibility.