Synthesis and utilization of luminescent hybrid films incorporating Y-CQDs for mercury ion detection

In this study, a highly selective and sensitive composite fluorescence sensor (Y-CODs @PVDF@PVP) was developed for the quantitative and visual detection of Hg2+ by electrostatic spinning carbon quantum dots (CQDs) with polyvinylidene fluoride (PVDF) and polyethylene pyrrolidone (PVP). The Y-CODs @PVDF@PVP composite fluorescence sensor exhibited strong yellow fluorescence under ultraviolet light (365 nm), demonstrating stable detection capability for mercury (II) in water samples. The morphology, chemical composition, and optical properties of Y-CODs @PVDF@PVP were thoroughly investigated. Different quenching effects were observed in Y-CODs @PVDF@PVP based on varying concentrations of Hg2+, enabling accurate determination of Hg2+. The achieved detection limit was 9.27 nM. Both static quenching and dynamic quenching mechanisms contributed to the observed results. Notably, the method successfully detected Hg2+ in real water samples from Beichuan Lake as well as rice samples, yielding satisfactory outcomes. Furthermore, when combined with software image analysis, quantitative and visual detection of field Hg2+ levels was accomplished using the composite fluorescence sensor. This research provides valuable insights for developing portable sensors aimed at monitoring harmful substances in water.