With the in-depth study of nanozymes, the specificity and catalytic activity of nanozymes still need to be improved for their diverse applications. Here, we report the preparation of Fe/C/Bi₂O₃ by thermal activation of Fe-doped Bi MOFs (FeBi MOFs) under an air atmosphere. It is found that the Fe/C/Bi₂O₃ has excellent peroxidase mimic activity due to the synergistic effect between two metals, while Fe is the crucial catalytic active site. The presence of abundant carboxyl groups gives it a high affinity for H₂O₂ with a low K_m of 0.076, which is about 49 times lower than that of HRP. The results of radical quenching and ESR experiments indicate that the main reactive oxygen species during TMB oxidation reaction are •OH and O₂^•–. By combining Fe/C/Bi₂O₃ nanozymes with two natural enzymes, i.e., acetylcholinesterase (AChE) and choline oxidase (ChOx), a three-enzyme (Fe/C/Bi₂O₃, AChE, ChOx) cascade system is proposed for the colorimetric sensing of dichlorvos with a wide linear range from 0.60 to 100 μg L⁻¹ and a low limit of quantitation of 0.60 μg L⁻¹. This work not only provides a new strategy for the design and preparation of high activity Fe/C/Bi₂O₃ nanozymes, but also demonstrats their potential use in environmental analysis.

随着纳米酶研究的深入，纳米酶的特异性和催化活性仍需提高以适应其多样化的应用。在这里，我们报道了在空气气氛下通过热活化Fe掺杂Bi MOF（FeBi MOF）制备Fe/C/Bi ₂ O _{3 。}研究发现，由于_{两种金属之间的协同作用，Fe/C/Bi 2} O _{3具有优异的过氧化物酶模拟活性}，而Fe是关键的催化活性位点。_{丰富的羧基基团的存在使其对 H 2} O ₂具有高亲和力，且K _m较低0.076，比HRP低约49倍。自由基猝灭和ESR实验结果表明， TMB氧化反应过程中主要的活性氧是•OH和O₂^•–。通过将Fe/C/Bi₂O₃纳米酶与乙酰胆碱酯酶(AChE)和胆碱氧化酶(ChOx)两种天然酶结合，形成三酶(Fe/C/Bi ₂O₃、AChE、ChOx)级联系统^{提议用于敌敌畏的比色传感，具有 0.60 至 100 μg L -1}的宽线性范围^{和 0.60 μg L -1}的定量下限。这项工作不仅为高活性Fe/C/Bi ₂ O ₃纳米酶的设计和制备提供了新的策略，而且展示了它们在环境分析中的潜在用途。