Abstract

Single-atom catalysts (SACs) have garnered considerable attention owing to their impeccable catalytic activity and unique ability to elucidate the active site. In this work, we synthesized iron-doped single-atom catalysts (Fe SACs) via a soft-template sacrificial approach, which exhibited peroxidase activity. Further investigations revealed that Fe SACs were capable of catalyzing the generation of highly reactive hydroxyl radicals (•OH) from hydrogen peroxide (H₂O₂), which facilitated the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to oxTMB, resulting in a discernible color change from colorless to blue. According to the exceptional peroxidase activity of Fe SACs, we designed and fabricated a colorimetric sensor by combining uricase and TMB, achieving highly sensitive and selective detection of uric acid over a wide range of concentrations (0.1–50 μM), with a low detection limit of 0.039 μM (3σ/k). Finally, we demonstrated the feasibility of our sensor in detecting uric acid in real human urine samples, yielding satisfactory recoveries and low relative standard deviations.

Graphical abstract

中文翻译：

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基于具有过氧化物酶活性的铁掺杂单原子催化剂比色法检测尿酸

摘要

单原子催化剂（SAC）由于其无可挑剔的催化活性和阐明活性位点的独特能力而引起了相当大的关注。在这项工作中，我们通过软模板牺牲方法合成了铁掺杂单原子催化剂（Fe SAC），该催化剂表现出过氧化物酶活性。进一步的研究表明，Fe SAC能够催化过氧化氢（H ₂ O ₂）产生高活性羟基自由基（·OH），从而促进3,3',5,5'-四甲基联苯胺（TMB）的氧化到 oxTMB，导致可辨别的颜色从无色变为蓝色。根据Fe SACs优异的过氧化物酶活性，我们结合尿酸酶和TMB设计并制作了比色传感器，实现了较宽浓度范围（0.1-50 μM）尿酸的高灵敏度、选择性检测，且检测限低0.039 μM (3σ/k)。最后，我们证明了我们的传感器在检测真实人体尿液样本中尿酸的可行性，产生令人满意的回收率和较低的相对标准偏差。

图形概要