PVP-capped Pt NPs-depended catalytic nanoprobe for the simultaneous detection of Hg2+ and Ag+

Mercury ions (Hg 2+ ) and silver ions (Ag + ) are assigned to the highest toxicity class of heavy metal pollution. Here, a novel sensor is firstly developed for the simultaneous detection of coexisting Ag + and Hg 2+ in aqueous solution, depending on the catalytic properties of poly(vinyl pyrrolidone) (PVP)-capped platinum nanoparticle (Pt NPs) and the strong chelation of EDTA to Hg 2+ . PVP-capped Pt NPs exhibit uniform morphology and possess great intrinsic peroxidase-like activity in comparison to citrate-capped Pt NPs, PVP-capped Ru NPs and Ir NPs, attributing to the enhanced catalytic efficiency determined by loosely packed PVP and the excellent catalytic decomposition activities of H 2 O 2 . Hg 2+ and Ag + could induce remarkable inhibition of the peroxidase-like activity of Pt NPs by changing the electronic state of the active sites through metallophilic interactions. The selective and simultaneous detection of Hg 2+ and Ag + was realized via the addition of ethylenediaminetetraacetate (EDTA), which could successfully mask Hg 2+ but had negligible effect on Ag + . The proposed approach inspires new designs of novel catalytic nanoprobes for the multi-analyte assay of heavy metal ions .