To reliably monitor dopamine (DA), a common neurotransmitter, a kind of nano CeO/CuO modified carboxylated chitosan nanozyme (CeO/CuO@CC) was constructed under microwave-assisted conditions. The proposed CeO/CuO@CC exhibited superior synergistic- enhancement oxidase-like activity, with high specific surface area and superior stability. It could accelerate the oxidization of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue oxTMB in the air. What’s more, the presence of trace DA could exclusively change the enzyme-like activity of CeO/CuO@CC, accompanied with visual color changes from blue to colorless. Under the optimized conditions, there expressed double ratiometric linear relationships between lg(/)/lg() and , with a large linear range between 6.0 × 10 and 1.0 × 10 M of DA. When applied for visual detection of DA in real samples, the detection limit was low to 2.0 × 10 M with RSD % less than 4.14 %. The mechanisms for enhanced oxidase-mimic activity of CeO/CuO@CC and its selective detection of DA were proposed. This work will offer an insight to design efficient nanozyme for visual detection of bio-analytes in practice.

中文翻译：

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基于纳米 CeO2/CuO 修饰羧化壳聚糖催化信号放大的多巴胺实际比色法可靠监测


为了可靠地监测常见神经递质多巴胺（DA），在微波辅助条件下构建了一种纳米CeO/CuO修饰的羧化壳聚糖纳米酶（CeO/CuO@CC）。所提出的CeO/CuO@CC表现出优异的协同增强氧化酶样活性，具有高比表面积和优异的稳定性。在空气中能加速无色3,3',5,5'-四甲基联苯胺(TMB)氧化成蓝色oxTMB。更重要的是，微量DA的存在可以专门改变CeO/CuO@CC的类酶活性，并伴随视觉颜色从蓝色到无色的变化。在优化条件下，lg(/)/lg()和 之间呈现双比例线性关系，在 DA 的 6.0 × 10 和 1.0 × 10 M 之间具有较大的线性范围。用于实际样品中DA的目视检测时，检测限低至2.0×10M，RSD%小于4.14%。提出了 CeO/CuO@CC 增强氧化酶模拟活性的机制及其对 DA 的选择性检测。这项工作将为设计有效的纳米酶以在实践中视觉检测生物分析物提供见解。