Malachite green (MG) is an organic dye compound that is frequently used as a fungicide and antiseptic in aquaculture. However, human or animal exposure to MG causes carcinogenic, teratogenic and mutagenic effects. Herein, a novel fluorescent assay was designed for the detection of MG using manganese dioxide nanosheets (MnO₂ NS) as an energy acceptor to quench the fluorescence of branched poly(ethylenimine) carbon dots (BPEI-CDs) via Förster resonance energy transfer. When butyrylcholinesterase is introduced to form thiocholine in the presence of S-butyrylthiocholine iodide, MnO₂ NS can be recovered by thiocholine to Mn²⁺, resulting in restoration of the fluorescence of BPEI-CDs. Exploiting these changes in fluorescence intensity in the above system, a fluorescence probe was successfully developed for the quantitative detection of MG. Besides, this assay was applied to fish samples, verifying the high potential for practical application of the proposed sensor for the monitoring of MG in aquatic products.

孔雀石绿 (MG) 是一种有机染料化合物，在水产养殖中经常用作杀菌剂和防腐剂。然而，人类或动物接触 MG 会导致致癌、致畸和致突变作用。在此，设计了一种新型荧光检测方法，使用二氧化锰纳米片 (MnO ₂ NS) 作为能量受体，通过 Förster 共振能量转移来猝灭支链聚（乙烯亚胺）碳点 (BPEI-CD) 的荧光。当在 S-丁酰硫代胆碱碘化物存在下引入丁酰胆碱酯酶形成硫代胆碱时，MnO ₂ NS 可被硫代胆碱回收为 Mn ²⁺，导致 BPEI-CD 的荧光恢复。利用上述系统中荧光强度的这些变化，成功开发了一种用于定量检测MG的荧光探针。此外，该测定法应用于鱼类样品，验证了所提出的传感器在监测水产品中 MG 的实际应用的巨大潜力。