Hierarchical flower-like NiMnO₃ composites were facilely prepared by template-free hydrothermal treatment and calcined under mild conditions. Due to the strong ability to absorb oxygen, the as-prepared NiMnO₃ composites were endowed with oxidase-like activity to catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue product without H₂O₂. Investigations on the mechanism indicate that oxidase-like activity of NiMnO₃ composites originates from superoxide radical generation. The oxidase-like activity of the NiMnO₃ composites was selectively inhibited by hydroquinone (HQ), which could reduce oxTMB to colorless TMB and could result in significant blue color fading. With increasing HQ concentration, the absorbance at 652 nm decreased gradually. A colorimetric method based on the NiMnO₃ composite was established for the detection of the concentration of HQ in water and practical samples. This assay was simple, rapid, sensitive, and selective for detecting HQ with a low detection limit of 0.68 μM and an excellent linear range of 1–85 μM. This colorimetric sensor could be effectively applied for the detection of HQ in real water samples with RSD < 3.89% (n = 3) and Er < 2.17% (n = 3). The above results illustrated that the NiMnO₃ composites have outstanding potential for application in environmental chemistry.

中文翻译：

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花状 NiMnO3 作为氧化酶模拟物的制备用于比色检测对苯二酚

通过无模板水热处理和在温和条件下煅烧，可以很容易地制备出分层花状NiMnO ₃复合材料。由于具有很强的吸氧能力，所制备的 NiMnO ₃复合材料具有氧化酶样活性，可催化 3,3',5,5'-四甲基联苯胺 (TMB) 氧化为不含 H ₂ O的蓝色产物₂ . 机理研究表明，NiMnO ₃复合材料的类氧化酶活性源于超氧自由基的产生。NiMnO ₃的氧化酶样活性复合材料被氢醌 (HQ) 选择性抑制，这可以将 oxTMB 还原为无色 TMB，并可能导致显着的蓝色褪色。随着 HQ 浓度的增加，652 nm 处的吸光度逐渐降低。建立了基于NiMnO ₃复合物的比色法检测水和实际样品中HQ的浓度。该检测方法简单、快速、灵敏且选择性地检测 HQ，检测限低为 0.68 μM，线性范围为 1–85 μM。该比色传感器可有效应用于实际水样中 HQ 的检测，RSD < 3.89% ( n = 3) 和 Er < 2.17% ( n = 3)。上述结果说明 NiMnO ₃ 复合材料在环境化学中具有突出的应用潜力。