Abstract In this paper, four kinds of Ag2WO4 materials were synthesized via facile hydrothermal methods, which were developed as highly efficient biomimetic catalysts for the first time. These Ag2WO4 materials exhibited distinct oxidase-like activities owing to their different crystal structures, morphologies and surface properties. Among them, Ag@Ag2WO4 nanorods (AWNRs-9) exhibited the best intrinsic oxidase mimetic performance, which were composed of Ag nanoparticles (NPs) loading on the surface of Ag2WO4 nanorods (NRs). It is found that the introduction of Ag NPs can significantly enhanced the oxidase-like catalytic activity due to the synergistic effect between Ag NPs and Ag2WO4 NRs. In addition, the catalytic oxidation reaction of 3,3′,5,5′-tetramethylbenzidine by AWNRs-9 was dramatically and selectively enhanced due to the mercury-stimulated effect. Thus, a simple, rapid and sensitive method for colorimetric detection of Hg2+ was developed, displaying a good linear response in the range of 0.25 μM to 8.0 μM with a detection limit of 1.6 nM. This assay method also showed a high selectivity, good stability and favorable practicability. It was successfully applied to the detection of Hg2+ in real water samples. This sensing system is expected to hold bright prospects for quantitative detection of Hg2+ in biological, environmental, and food fields.

中文翻译：

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用于比色检测 Hg2+ 的 Ag@Ag2WO4 纳米棒增强的氧化酶样活性

摘要 本文通过简便的水热法合成了四种Ag2WO4 材料，首次将其开发为高效的仿生催化剂。这些 Ag2WO4 材料由于其不同的晶体结构、形态和表面性质而表现出不同的氧化酶样活性。其中，Ag@Ag2WO4纳米棒（AWNRs-9）表现出最好的内在氧化酶模拟性能，其由负载在Ag2WO4纳米棒（NRs）表面的Ag纳米颗粒（NPs）组成。发现由于Ag NPs和Ag2WO4 NRs之间的协同作用，Ag NPs的引入可以显着增强类氧化酶催化活性。此外，3,3',5的催化氧化反应，由于汞刺激效应，AWNRs-9 的 5'-四甲基联苯胺显着且选择性地增强。因此，开发了一种简单、快速且灵敏的 Hg2+ 比色检测方法，在 0.25 μM 至 8.0 μM 范围内显示出良好的线性响应，检测限为 1.6 nM。该测定方法还显示出选择性高、稳定性好、实用性强。成功应用于实际水样中Hg2+的检测。该传感系统有望在生物、环境和食品领域对 Hg2+ 进行定量检测。该测定方法还显示出选择性高、稳定性好、实用性强。成功应用于实际水样中Hg2+的检测。该传感系统有望在生物、环境和食品领域对 Hg2+ 进行定量检测。该测定方法还显示出选择性高、稳定性好、实用性强。成功应用于实际水样中Hg2+的检测。该传感系统有望在生物、环境和食品领域对 Hg2+ 进行定量检测。