Metal-organic framework modified open-cavity optical fiber Fabry-Pérot interferometer for volatile organic compound detection.

Detection of volatile organic compounds (VOCs) is crucial in industrial production, environmental monitoring, and public safety. VOCs sensors need to be intrinsically safe, given the flammability and toxicity of common VOCs. Fiber optic sensors offer a passive and flexible solution for VOCs detection, attracting significant attention from researchers. In this study, ZIF-8, a subset of metal-organic frameworks, is applied to a side-polished silicon wafer, forming an open-cavity optical fiber Fabry-Pérot interferometer (FPI) with a fiber patch cable and a 3D-printed structural part. The sensing performance for prevalent VOCs, including methylbenzene, methanol, and ethanol, is experimentally explored, exhibiting sensitivities of 0.118 p.m./ppm, 0.177 p.m./ppm, and 0.412 p.m./ppm, respectively. Sensitivity differences are analyzed and demonstrated at the molecular level. The proposed technologies offer advantages such as easy fabrication, intrinsic safety, small size, and good selectivity, providing an alternative for VOCs detection in industrial production.