Long Gang, Wan Liang, Xia Binyun, Zhao Chao, Niu Kunpeng, Hou Jianguo, Lyu Dajuan, Li Litong, Zhu Fangdong, Wang Ning
National Engineering Research Center of Fiber Optic Sensing Technology and Networks, Wuhan University of Technology, Wuhan 430070, China.
State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Yangtze Optical Fibre and Cable Joint Stock Limited Company, Wuhan 430073, China.
Materials (Basel). 2022 Oct 24;15(21):7449. doi: 10.3390/ma15217449.
The measurement of pH has received great attention in diverse fields, such as clinical diagnostics, environmental protection, and food safety. Optical fiber sensors are widely used for pH sensing because of their great advantages. In this work, an optical fiber pH sensor is fabricated, by combining the merits of the multimode interference configuration and pH-sensitive polyaniline/polyacrylic acid (PAni/PAA) coatings, which was successfully in situ deposited on the no-core fiber (NCF) by the layer-by-layer (LBL) self-assembly method. The sensors' performance was experimentally characterized when used for pH detection. It has a high sensitivity of 0.985 nm/pH and a great linear response in a universal pH range of 2-12. The response time and recovery time is measured to be less than 10 s. In addition, its temperature sensitivity is tested to be about 0.01 nm/°C with a low temperature crosstalk effect, which makes it promising for detecting pH in the liquid phase with temperature variation. The sensors also demonstrated easy fabrication, good stability, and repeatability, which are adapted to pH detection in most practical applications.
pH值的测量在临床诊断、环境保护和食品安全等多个领域受到了极大关注。光纤传感器因其巨大优势而被广泛用于pH传感。在这项工作中，通过结合多模干涉结构和pH敏感的聚苯胺/聚丙烯酸（PAni/PAA）涂层的优点，制备了一种光纤pH传感器，该涂层通过层层（LBL）自组装方法成功原位沉积在无芯光纤（NCF）上。当用于pH检测时，对传感器的性能进行了实验表征。它具有0.985 nm/pH的高灵敏度，在2-12的通用pH范围内具有良好的线性响应。测量的响应时间和恢复时间小于10 s。此外，测试其温度灵敏度约为0.01 nm/°C，温度串扰效应低，这使得它有望在温度变化的情况下检测液相中的pH值。该传感器还具有易于制备、良好的稳定性和可重复性，适用于大多数实际应用中的pH检测。
