MB-硬脂酸复合薄膜光波导传感器检测氯化氢气体

摘要

利用旋转甩涂法将亚甲基蓝(MB)掺杂的硬脂酸溶液涂成薄膜固定在钾离子(K+)交换玻璃光波导表面上,研制了MB-硬脂酸复合薄膜/K+交换玻璃光波导传感器,并对酸性气体进行了检测.该复合薄膜与氯化氢(HCl)气体作用时,薄膜颜色从深蓝色变为浅蓝色,导致薄膜对倏逝波的吸收降低,使传感器的输出光强度增强.结果表明,在室温下该传感器对低浓度的氯化氢气体仍具有较好的重复性和选择性响应,可检测到体积分数为1×10-6％的HCl气体,响应和恢复时间分别为7和20 s,相对标准偏差为±6.06％.该传感器具有灵敏度高、响应-恢复速度快、可逆性好、成本低和容易制备等特点.%The methylene blue (MB) doped stearic acid composite film was deposited onto the surface of a single mode potassium ion(K+) exchanged glass optical waveguide(OWG) by spin coated method, the OWG sensor was fixed on the OWG sensor testing system to detect acidic gases. In the presence of hydrogen chloride ( HC1) gas, the color of the MB-stearic acid composite film changed from dark blue to light blue, this led to a decrease in the evanescent absorbance of the film, increased output light intensity of the sensor. The experimental results show that the sensor has high repeatability and selectivity towards lower concentration HC1 gas at room temperature, its response time and recovery time for 1×10-6 % HCl gas are 7 and 20 s, respectively, the relative standard deviation(RSD) of output light intensity is ±6.06% at this concentration. The sensor has high sensitivity, fast response and recovery speed, good reversibility, low cost and is easily fabricated.