A multifunctional fluorescent probe for visualizing H2S in wastewater with portable smartphone via fluorescent paper strip and sensing GSH in vivo

Highlights: • GH could simultaneously detect H₂S in wastewater and GSH in living cells. • The mechanism of GH towards H₂S/GSH was demonstrated through fluorescence, UV–vis, ¹H NMR and DFT calculations. • Portable fluorescent paper strips are widely used in field inspections. • Fluorescent paper strips of GH integrated with smartphone can realize quantitative monitor of H₂S in wastewater. In this paper, a bifunctional tri-site fluorescent probe was designed for the first time not only for visualization and quantitative analysis of sensing H₂S in wastewater by coupling paper strip and smartphone (Color recognizer, Xiyi Technology) but also for sensitively monitoring GSH in living cells, which relied on different emission channels and the pH of solutions. The recognition properties of GH towards H₂S/GSH were satisfactorily demonstrated through fluorescence, UV–vis, ¹H NMR and DFT calculations. More importantly, integrated with the paper strip, portable smartphone-sensing platform with a color recognizer app would accomplish cost-effective and rapid assays for colorimetric water quality testing, which displayed huge application potential in fields of environmental monitoring.