Mercury speciation based on mercury-stimulated peroxidase mimetic activity of gold nanoparticles
Mercury speciation based on mercury-stimulated peroxidase mimetic activity of gold nanoparticles
复制标题
基于金纳米粒子的汞刺激过氧化物酶模拟活性的汞形态
DOI：
10.1039/d0an00803f
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发表时间：
2020
期刊：
影响因子：
4.2
通讯作者：
Wang Jian-Hua
中科院分区：
文献类型：
--
作者：
Yang Jian-Yu;Jia Xin-Di;Wang Xiao-Yan;Chen Ming-Li;Yang Ting;Wang Jian-Hua
汞的形态在环境和生物分析中具有重要意义，因为其在人体内的毒性和代谢行为因物种而异。纳米材料辅助光学传感器广泛用于汞离子检测，但很少应用于汞形态分析。在这项工作中，我们在不同还原剂的帮助下，基于金纳米颗粒的汞刺激过氧化物酶模拟活性，开发了一种新颖的汞形态比色传感策略。在弱还原剂存在下，只有无机汞可以还原为Hg0，而在强还原剂存在下，无机汞和有机汞都可以还原为Hg0。由于Hg和Au之间的高亲和力，Hg0以Au-Hg汞齐的形式沉积在AuNP表面，导致金纳米粒子的过氧化物酶模拟活性显着增强。基于此效应，以3,3',5,5'-四甲基联苯胺（TMB）为底物可以检测无机汞和总汞。无机汞和总汞的检测限分别为 1.9 和 0.9 nM，范围为 5–100 nM。由于金汞相互作用的特异性，该传感系统的选择性很高。鱼样品中的有机汞分析和人头发样品中的汞形态进一步证明了其实际应用。
Mercury speciation is of significant importance in environmental and biological analysis because its toxicity and metabolic behavior in the human body differ among species. Nanomaterial-assisted optical sensors are widely used for mercury ion detection but rarely applied in mercury speciation analysis. In this work, we develop a novel colorimetric sensing strategy for mercury speciation based on mercury-stimulated peroxidase mimetic activity of gold nanoparticles with the assistance of different reductants. In the presence of a weak reductant, only inorganic mercury can be reduced to Hg0, whereas both inorganic mercury and organic mercury can be reduced to Hg0 in the presence of a strong reductant. Due to the high affinity between Hg and Au, Hg0 deposits on the AuNP surface in the form of a Au–Hg amalgam, leading to a remarkable enhancement of peroxidase mimetic activity of gold nanoparticles. On the basis of this effect, inorganic mercury and total mercury can be detected by using 3,3′,5,5′-tetramethylbenzidine (TMB) as the substrate. The limits of detection for inorganic mercury and total mercury are 1.9 and 0.9 nM within 5–100 nM, respectively. The selectivity of this sensing system is high due to the specificity of Au–Hg interaction. Its practical applications are further demonstrated by organic mercury analysis in a fish sample and mercury speciation in a human hair sample.