Rapid and accurate detection of phenolic wastewater from industries has created global concern. Herein, core–shell magnetic cellulose nanocrystal supported MOF (Fe₃O₄/CNC@ZIF-8) with robust peroxidase-like activity was synthesized with tannic acid as modifier and bridge. The peroxidase-mimic catalytic activity of as-prepared Fe₃O₄/CNC@ZIF-8 was further investigated using o-phenylenediamine (OPD) as peroxidase substrates in the presence of H₂O₂. Moreover, the experimental conditions were optimized and the kinetic analysis results showed that Fe₃O₄/CNC@ZIF-8 had higher affinity towards both the substrate OPD and H₂O₂ than horseradish peroxidase (HRP). Finally, a phenol colorimetric assay with a linear range of 2–200 µM and a detection limit of 0.316 µM was constructed. The catalytic mechanism of Fe₃O₄/CNC@ZIF-8 with phenol was further investigated by fluorescence test and the generated ·OH was proved to act a crucial role to produce quinoid radicals. Additionally, the synthesized magnetic material had excellent stability and recyclability and ease to separation. These results suggest that the Fe₃O₄/CNC@ZIF-8 may be one of the promising candidates as peroxidase mimic for colorimetric detection of phenol.

快速准确地检测工业中的酚类废水引起了全球关注。在此，以单宁酸作为改性剂和桥联，合成了具有强过氧化物酶活性的核壳磁性纤维素纳米晶负载的 MOF（Fe ₃ O ₄ /CNC@ZIF-8）。在 H ₂ O ₂存在下，使用邻苯二胺 (OPD) 作为过氧化物酶底物进一步研究了所制备的 Fe ₃ O ₄ /CNC@ZIF-8的过氧化物酶模拟催化活性。此外，优化了实验条件，动力学分析结果表明Fe ₃ O ₄ /CNC@ZIF-8对底物OPD和H ₂具有更高的亲和力O ₂比辣根过氧化物酶（HRP）。最后，构建了线性范围为 2–200 µM 和检测限为 0.316 µM 的苯酚比色法。通过荧光测试进一步研究了Fe ₃ O ₄ /CNC@ZIF-8与苯酚的催化机理，并证明生成的·OH在产生醌自由基中起关键作用。此外，合成的磁性材料具有优异的稳定性和可回收性，易于分离。这些结果表明，Fe ₃ O ₄ /CNC@ZIF-8 可能是作为过氧化物酶模拟物用于苯酚比色检测的有前途的候选物之一。