Laser Induced Fluorescence for in-situ Detection of Typical Heavy Metals in Groundwater

In-site detection of heavy metals in groundwater is important to quickly evaluate pollution. Laser induced fluorescence (LIF) utilizes specific fluorescent probes to generate/quench fluorescence in the presence of heavy metals, thereby achieving heavy metals detection, which could quickly identify heavy metals and non-destructively obtain their valence states. This work summarizes principle and equipment of and its application for in-situ detection of typical heavy metals in groundwater. At present, LIF probes used for heavy metal detection include organic fluorescent probes mainly composed of small molecule probes, macromolecules, and AIE probes, as well as nanomaterial probes represented by gold nanoclusters, QDs, and MOFs. These synthesized probes and the corresponding constructed sensors indicate that LIF holds significant advantages in heavy metal detection in groundwater. Although the achievements in the development of LIF equipment for heavy metal detection in groundwater are not as rich as those in sensing methods, LIF equipment for several heavy metals have been developed, demonstrating good application prospects. Future research will focus on identifying the controlling factors of heavy metals in groundwater and developing anti-interference techniques, synthesizing novel fluorescent probes for LIF sensor, integrating sensing components into LIF equipment, and standardizing LIF detection process.