Mercury ions (Hg²⁺) 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 Hg²⁺ 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 Hg²⁺. 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 H₂O₂. Hg²⁺ 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 Hg²⁺ and Ag⁺ was realized via the addition of ethylenediaminetetraacetate (EDTA), which could successfully mask Hg²⁺ 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.

汞离子（Hg ²⁺）和银离子（Ag ⁺）被归为重金属污染的最高毒性类别。在这里，首先开发了一种新型传感器，用于同时检测水溶液中同时存在的Ag ⁺和Hg ²⁺，这取决于聚乙烯吡咯烷酮（PVP）包覆的铂纳米颗粒（Pt NPs）的催化性能和强螯合EDTA对Hg ^2+的影响。与柠檬酸盐封端的Pt NPs，PVP封端的Ru NP和Ir NPs相比，PVP封端的Pt NP表现出均一的形态并具有强大的内在过氧化物酶样活性，这归因于通过松散包装的PVP确定的增强的催化效率和出色的催化分解作用H _2的活动O ₂。Hg ²⁺和Ag ⁺可以通过亲金属相互作用改变活性位点的电子状态，从而显着抑制Pt NPs的过氧化物酶样活性。通过加入乙二胺四乙酸盐（EDTA）可以选择性，同时检测Hg ²⁺和Ag ⁺，该溶液可以成功掩盖Hg ^2+，但对Ag ^+的影响可忽略不计。所提出的方法激发了用于重金属离子多分析物测定的新型催化纳米探针的新设计。