Two-Dimensional MoS₂ Nanosheet-Functionalized Optical Microfiber for Room-Temperature Volatile Organic Compound Detection

Two-dimensional (2D) transition-metal dichalcogenides such as molybdenum disulfide (MoS2) have received a great deal of attention for high-performance gas sensing applications. Unfortunately, before their translation to commercial use, several scientific problems remain to be solved. The challenges include poor stability in a humid environment, random deposition manner of MoS2 flakes that makes the process unscalable, and incomplete recovery at room temperature. Herein, we report a strategy for the room-temperature volatile organic compound (VOC) sensor using the optical microfiber sensing technology. We demonstrated well-controlled immobilization of MoS2 nanosheets onto the optical sensing region using the optical deposition technique. The experimental results show that the MoS2-functionalized optical microfiber sensor achieves high selectivity to polar aprotic and nonpolar VOCs. The sensor demonstrated high sensitivity of 0.0195, 0.0143, 0.0072, and 0.0058 nm/ppm to acetone, ethyl acetate, cyclohexane, and IPA, respectively. Finally, the repeatability and complete recovery capabilities of the sensor have also been validated in this work.