(3-Aminopropyl) triethoxysilane-based immobilization of Pt/WO₃ on a microfiber sensor for high sensitivity hydrogen sensing

A novel high stability hydrogen sensor based on a Pt/WO₃ coated single-mode tapered-no-core single-mode (STNCS) fiber interferometer is proposed and experimentally studied. The STNCS structure is treated by (3-Aminopropyl) triethoxysilane (APTES) and then coated with Pt/WO₃ nanorods. Compared to the traditional method of using poly (dimethylsiloxane) (PDMS) to adhere Pt/WO₃ nanorods on the fiber surface, the APTES modified fiber forms strong covalent bonds with Pt/WO₃ with stronger adhesion to the fiber surface, resulting in improved long-term stability. Experimental results show that the sensitivity of the sensor varies from − 31.05 nm/% to − 4.30 nm/% as the hydrogen concentration increases from 0% to 1.04%. The sensor also demonstrates good reproducibility, longer term stability and repeatability.