Dimethyl sulfoxide infiltrated photonic crystals for gas sensing

Colorimetric sensors were fabricated by embedding three dimensional (3D) inverse opal photonic crystal (IOPC) structure inside a dimethyl sulfoxide (DMSO) infiltrated carboxymethyl cellulose membrane for gas sensing. The DMSO infiltrated IOPC (DMSO-IOPC) carboxymethyl cellulose sensors can perform visual, on-site monitoring for analytes including alcohols, acetone and hydrogen peroxide (H₂O₂). After exposed to alcohols and acetone, the mean effective refractive index (RI) and lattice constant of DMSO-IOPCs were changed, which led to a redshift of diffraction peak of the incident light. Sequentially their structural color changed remarkably. The limit of detection (LOD) for methanol and ethanol vapors are 110 ppm and 102 ppm, respectively. The H₂O₂ sensor is also achieved by using DMSO-IOPCs, and the diffraction blue-shifted when they were exposed to H₂O₂ vapor. In addition, this DMSO-IOPC sensor shows excellent selectivity and reversibility. The sensing mechanism of the DMSO-IOPC membranes was explained and simulated using finite-different time-domain (FDTD) method, and the experimental results were consistent with the simulated results. The DMSO-IOPCs demonstrate promising potential for in-situ monitoring of alcohol vapors, and could be used for peroxides detection and as a cheap and minimally invasive breathalyzer.