ZnOHF-ZnO nanomaterial-coated macro-bend fiber triethylamine gas sensor working at room temperature

This study presents a room temperature triethylamine (TEA) gas sensor based on the macro-bend fiber. The sensor achieves the rapid and high sensitivity measurement of TEA gas by coating the bending section of the optical fiber with ZnOHF-ZnO nanomaterial. The macro-bend fiber structure increases the penetration depth of the evanescent field transmitting along the no-core optical fiber (NCF), what allowing more light to leak into layer of the gas-sensitive material and thus enhancing the sensitivity to TEA gas. Different sensing probes were fabricated and compared for the coating layers with ZnOHF and ZnOHF-ZnO, respectively. The results showed that the sensitivity of the ZnOHF-ZnO coated sensor was 0.0044 dB/ppm, which was three times higher than that of the ZnOHF-coated sensor. Other sensing performance was experimentally demonstrated with a limit of detection (LOD) of 1 ppm, a response time of 16 s, and a recovery time of 18 s, enabling fast detection for TEA gas. Finally, the working mechanism has been explained. This macro-bend fiber-based TEA gas sensor has the advantages of small size, low operating temperature, fast response time, and good selectivity, making it suitable for the rapid identification and detection of TEA gas.