Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, Yunnan, China.
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, Yunnan, China; Institute of Agro-Products Processing, Yunnan Academy of Agricultural Sciences, Kunming 650093, Yunnan, China.
J Hazard Mater. 2023 Jan 5;441:129919. doi: 10.1016/j.jhazmat.2022.129919. Epub 2022 Sep 6.
Methylmercury (MeHg) is one of the common organic species of mercury, and has much higher toxicity than inorganic mercury. Based on the selective enhancement of the activity of nanozyme (NA-CDs/AuNPs) by MeHg, a novel colorimetric nanoprobe for MeHg assay is proposed. The noradrenaline-based carbon dots (NA-CDs) as the reducing agent was applied to prepare the NA-CDs/AuNPs. The formation of gold amalgamation (Au@HgNPs) between nanozyme and MeHg allows to simultaneously accelerate the electron transfer from Au and Hg to NA-CDs and the generation of radicals (i.e. ∙OH, ∙O and ∙CH). The NA-CDs/AuNPs has an outstanding anti-interference performance even in the presence of different mercury. Further density functionality theory (DFT) calculations revealed that the formation of Au@HgNPs via MeHg contributes to the significantly lowered activation energy, resulting in the peroxidase-like activity generation and acceleration. This leads to rapid (10 min) and specific colorimetric detection of MeHg with the detection limit of 0.06 μg L. This introduces a novel method for simple and sensitive detection of MeHg, giving a new horizon for the assay of organometallic compounds.
甲基汞（MeHg）是汞的常见有机形态之一，其毒性比无机汞高得多。基于 MeHg 对纳米酶（NA-CDs/AuNPs）活性的选择性增强，提出了一种用于测定 MeHg 的新型比色纳米探针。基于去甲肾上腺素的碳点（NA-CDs）作为还原剂来制备 NA-CDs/AuNPs。纳米酶与 MeHg 之间形成的金汞齐（Au@HgNPs）可同时加速电子从 Au 和 Hg 转移到 NA-CDs 并产生自由基（即 ∙OH、∙O 和 ∙CH）。即使存在不同的汞，NA-CDs/AuNPs 也具有出色的抗干扰性能。进一步的密度泛函理论（DFT）计算表明，通过 MeHg 形成 Au@HgNPs 有助于显著降低活化能，从而产生和加速过氧化物酶样活性。这导致了对 MeHg 的快速（10 分钟）和特异性比色检测，检测限为 0.06 μg L。这为简单灵敏地检测 MeHg 引入了一种新方法，为有机金属化合物的测定开辟了新的前景。
