地下水重金属污染正在严重威胁环境安全和人体健康。荧光探针检测技术因具有灵敏度高、选择性好等优势，已成为检测重金属离子浓度的常用方法之一。受限于光源和光学系统的体积与成本等因素，现有重金属荧光检测装置无法满足现场原位检测需求。本文研制了一种地下水重金属荧光原位检测装置，其光学探头以紫外发光二极管（LED）为光源，采用共聚焦光路设计，荧光收集角范围可达102°，外径不超过60 mm，实现了小型化和低成本化。同时，以商用化台式荧光分光光度计作为参照设备，搭载相同的二价汞离子（Hg²⁺）荧光探针，开展了对比性能测试。实验结果表明，本文研发的装置具有良好的稳定性和线性响应特性，相关系数R²为0.989，检测限可达到1.47×10^-9，各项性能参数不亚于台式荧光分光光度计。

Heavy-metal pollution of groundwater is a severe threat to the environmental safety and human health. Owing to their high sensitivity and good selectivity, fluorescence probe detection methods have been commonly used to determine the concentration of heavy metals. Because of the large size and high cost of the light source and optical system, the current heavy-metal fluorescence detection devices cannot meet the demands of in situ detection. In this study, we develop an in situ fluorescence detection device for the analysis of heavy metals in groundwater samples. The optical detector of the device uses ultraviolet (UV) light-emitting diodes (LEDs) as the light source and exhibits a confocal optical path design with a fluorescence collection angle range and an outer diameter of up to 102° and 60 mm, respectively, to achieve miniaturization and decrease cost. A commercial benchtop fluorescence spectrophotometer was used as a reference device. The devices were equipped with identical Hg²⁺ ion fluorescent probes, and comparative performance tests were conducted. The experimental results demonstrate that the as-developed fluorescence detection device exhibits good stability and a remarkable linear response, with a correlation coefficient (R²) and detection limit of 0.989 and 1.47×10^-9, respectively. Furthermore, the performance parameters of the fluorescence detection device are comparable to those of the benchtop fluorescence spectrophotometer.