饮水中铅痕量的光波导高灵敏探测

High Sensitive Measurement of Lead Trace in Drinking Water Based on Optical Waveguide Configurations

提出了一种基于双面金属包覆波导结构的高灵敏光学传感器,利用入射激光在小角度入射时所激发的超高阶导模为探针,并结合铅离子与苯肼硫碳酰偶氮苯的特异性显色机理,对饮水中铅离子痕量进行低浓度探测。理论与实验结果研究表明,该光学传感器的检测极限可达到1μg/L,该方法是一种需样少、耗时短、实时性好、稳定性高和价格低廉的在线检测新技术,预计可为我国环境保护和食品安全领域提供一种全新的重金属离子检测路线。

An high sensitive optical sensor utilizing double metal cladding waveguide is proposed. Bsaed on the ultra high order guided modes in this sensor confriguration which are ultra sensitive to the imaginary part of the refractive index of the guide wave layer as probe, and combining with the specific color rendering mechanism of lead chromium ion and diphenylcarbazone,we detect the trace amounts of lead ion in water. The theoretical and experi-mental results indicate that the limit of detection has reached 1μg/L. This new method has a lot of advantages,such as lower specimen,shorter time,good real-time,high stabilization,lower cost and so on. This new kind of sensor will has an important influence in the environment protection and food security of our country.