Nanocomposite modified optical fiber: A room temperature, selective H2S gas sensor: Studies using ZnO-PMMA

Nanomaterial modified optical fiber sensor is studied for sensing H2S at room temperature for very low concentrations from 1 ppm to 5 ppm. ZnO nanoparticles were embedded into poly-methyl-metha-acrylate (PMMA) matrix and coated on the mirror tip of the single-mode fiber in the Fabry-Perot interferometric configuration to a 1550 nm laser source. The sensor response was found to be 1950 p.m. for 5 ppm gas. The detailed study of response of the sensor modified with nanocomposite (and their individual counterparts) suggested that the swelling property of PMMA offers enhanced gas adsorption opportunity and optical transparency of the ZnO nanoparticles exhibit sensing. A real-time sensor operating at room temperature is hence projected. [Display omitted] •An optical fiber based sensor to sense the toxic gas, hydrogen sulphide, selectively, is discussed.•This approach uses a combination of an optical interferometry technique along with nanomaterials for sensing.•It uses PMMA in the composite which uses the chemical swelling property of the polymer and specific sensitivity of ZnO.•The cross-sensitivity is also documented by using oxygen gas.