A rapid acid vapor detector based on spiropyran-polymer composite

Abstract A capillary coating with a photochromic spiropyran doped polydimethylsiloxane composite for HCl vapor detection is developed. By this simple method, that is, by the waveguiding capacity of capillary, the responsive fluorescence of spiropyran is efficiently collected to the spectrometer. A rapid sensing as short as 5 s to sub-ppm levels HCl vapor concentration (0.15–3 ppm) is achieved. Furthermore, the UV-responsive properties of spiropyran doped polydimethylsiloxane composite are investigated. Intriguingly, a wide range of UV intensity (20 μW/cm2 to 1447 μW/cm2) is able to be linearly responded through the proposed strategy. This method does not need complex fabrication processes or chemical treatments but provides a robust signal and rapid response for small acid vapor concentration detection. We envision that this research may enhance the potential of photochromism for applications in acid vapor sensing and UV dosimeter.