Water-soluble polymer dots formed from polyethylenimine and glutathione as a fluorescent probe for mercury(II)

Water-soluble fluorescent polymer dots (PDs) were prepared from polyethylenimine and glutathione and are shown to be viable fluorescent probes for selective and sensitive determination of Hg(II). The PDs possess bright blue fluorescence (with excitation/emission peaks at 340/462 nm) which is quenched on addition of Hg(II). Based on these findings, a fluorometric assay was worked out. Fluorescence linearly drops in the 0.1 to 100 μM Hg(II) concentration range, and the limit of detection is 32 nM. Graphical abstract The fluorescence of polymer dots prepared from glutathione and polyethyleimine (G-PEI PDs) is selectively quenched by Hg²⁺, and this finding was applied to the determination of Hg²⁺ in environmental water samples.