A fiber optics sensor based on the structure of no-core fiber/few-mode fiber coated with a smart hydrogel membrane/no-core fiber, cascading a fiber Bragg grating for temperature monitoring was developed to detect the concentration of Pb²⁺ in aqueous solution. It is the first time that a phase-modulated fiber sensor is used to measure the concentration of Pb²⁺ in aqueous solution. When the concentration of Pb²⁺ changes, the specific adsorption of the hydroxyethyl methacrylate crosslinked hydrogel on Pb²⁺ will change the refractive index of the sensing membrane, and will shift the interference fringe of the sensor in optical spectrum. The process is simple and friendly to environment, and does not produce any harmful substance. The fiber sensor with high sensitivity of 8.155 × 10⁵nm/(mol/L) and the estimated detection limit of Pb²⁺ concentration of 2.452 × 10⁻⁸ mol/L at the spectral resolution of 0.02 nm. The sensor has the advantages of high concentration resolution, low cost, remote detection ability, etc. It has good application prospect in the detection of Pb²⁺ concentration.

开发了一种基于无芯光纤/少模光纤结构的光纤传感器，该结构涂覆有智能水凝胶膜/无芯光纤，级联光纤布拉格光栅用于温度监测，用于检测水溶液中 Pb ²⁺的浓度。解决方案。这是首次使用相位调制光纤传感器测量水溶液中Pb ²⁺的浓度。当Pb ²⁺浓度变化时，甲基丙烯酸羟乙酯交联水凝胶对Pb ²⁺的比吸附将改变传感膜的折射率，并在光谱中移动传感器的干涉条纹。工艺简单，对环境友好，不产生任何有害物质。该光纤传感器具有8.155 × 10 ⁵ nm/(mol/L) 的高灵敏度和0.02 nm 光谱分辨率下Pb ²⁺浓度的估计检测限为2.452 × 10 ^-8 mol/L。该传感器具有浓度分辨率高、成本低、远程检测能力强等优点，在Pb ²⁺浓度检测中具有良好的应用前景。