Visualization of microcystin-LR and sulfides in plateau lakes

In eutrophic water bodies, sulfides are closely related to the growth of cyanobacteria and the production of microcystin-LR (MC-LR). To date, the underlying interaction mechanism between a sulfides and MC-LR remains controversial. Thus, visually presenting the distribution characteristics of sulfides and MC-LR in contaminated water is crucial. Here, we propose a novel and expeditious practical approach, utilizing fluorescence probe technology, to assess the distribution characteristics of MC-LR and sulfur in natural lakes. We have developed novel probes, pib2, to detect HSO₃^- and HS^-, and pib18, to simultaneously identify MC-LR and sulfides. Through correlation analysis of fluorescence data and physicochemical indicators at sampling points, it is found that fluorescence data has good correlation with sulfides and MC-LR, and speculated that pib2 and pib18 may be able to detect sulfides and MC-LR in lakes. Using this method, we rapidly obtained the distribution of MC-LR and sulfur in Qilu and Erhai Lakes. Notably, for the first time, we rapidly displayed the distributions of sulfides and MC-LR across lakes by the fluorescent probe technology.