提出了一种新型的光波导氨敏传感器,将光波导中消逝波理论与纳米多孔薄膜技术相结合,在玻璃薄膜光波导上制备一层纳米TiO2多孔薄膜,并将氨敏试剂(BTB)固定在纳米TiO2多孔薄膜中,利用导波光的消逝场实时地探测敏感薄膜对导波光的吸收,实现了对氨气的探测,检测下限达到1 ppm。同时对比了致密敏感薄膜和多孔敏感薄膜对氨气的响应,后者灵敏度约为前者的3倍,最后讨论了相对湿度对检测结果的影响。由于所制作的敏感薄膜对光谱的吸收具有可逆性,因此该传感器具有良好的重复性。

A novel ammonia sensor based on evanescent-field theory and nanoporous thin film was developed. Nano-TiO2 porous thin film on glass film optical waveguide was prepared, and acid-base indicator(BTB) was fixed on the nano-TiO2 porous thin film. The detection of ammonia by detecting sensitive thin film absorption of guidwave was achieved, and the detection limit was 1 ppm. The density-sensitive film and porous-sensitive flim responses to ammonia were compared, the latter sensitivity was about three times the former. Because the nano-porous thin film on the absorption spectrum was reveraible, the sensor had good repeatability.