Monitoring acetylcholinesterase (AChE) and its inhibitors is of importance for early diagnosis and therapy of neurological diseases. Herein, N-doped carbon nanotubes supported Fe–Mn dual-single-atoms (FeMn DSAs/N-CNTs) were fabricated by a simple pyrolysis, as thoroughly figured out by a series of the characterization techniques. The peroxidase-like activity of FeMn DSAs/N-CNTs was investigated by catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to generate rich hydroxyl radicals (·OH) in the H₂O₂ system, which effectively catalyzed colorless TMB oxidation to blue oxidized TMB (ox-TMB). Besides, the peroxidase-like activity was greatly weakened by thiocholine (derived from AChE), accompanied by making blue ox-TMB fade. Impressively, the highly improved peroxidase-like property is further evidenced by density functional theory (DFT) calculations, where the dual-single atoms show a lower energy barrier (0.079 eV) and their interactions with the N-CNTs played critical roles for producing the oxygen radicals. By virtue of the nanozyme, a low-cost, specific, and sensitive colorimetric sensor was built for detection of AChE with a broader linear range of 0.1–30 U L^–1 and a lower limit of detection (LOD, 0.066 U L^–1), combined with its feasible analysis in human serum samples. Also, this platform was applied for measuring huperzine A inhibitor with a wide linear scope of 5–500 nM and a LOD down to 4.17 nM. This strategy provides a low-cost and convenient approach for early clinical diagnosis and drug development.

中文翻译：

---

N 掺杂碳纳米管负载 Fe-Mn 双单原子纳米酶，协同增强过氧化物酶活性，用于乙酰胆碱酯酶及其抑制剂的灵敏比色检测

监测乙酰胆碱酯酶 (AChE) 及其抑制剂对于神经系统疾病的早期诊断和治疗具有重要意义。在此，N 掺杂的碳纳米管负载 Fe-Mn 双单原子 (FeMn DSAs/N-CNTs) 是通过简单的热解制备的，正如一系列表征技术所彻底弄清楚的那样。_{通过催化氧化 3,3',5,5'-四甲基联苯胺 (TMB) 在 H 2} O ₂中产生丰富的羟基自由基 (·OH)，研究了 FeMn DSAs/N-CNTs 的类过氧化物酶活性系统，有效催化无色TMB氧化成蓝色氧化TMB（ox-TMB）。此外，硫代胆碱（来源于 AChE）大大削弱了过氧化物酶样活性，同时使 blue ox-TMB 褪色。令人印象深刻的是，密度泛函理论 (DFT) 计算进一步证明了高度改善的类过氧化物酶特性，其中双单原子显示出较低的能垒 (0.079 eV)，并且它们与 N-CNT 的相互作用对于产生氧自由基。凭借纳米酶，构建了一种低成本、特异性和灵敏的比色传感器，用于检测 AChE，具有更宽的线性范围 0.1–30 UL ^–1和检测下限（LOD，0.066 UL ^–1), 结合其在人血清样本中的可行性分析。此外，该平台还用于测量线性范围为 5–500 nM 且 LOD 低至 4.17 nM 的石杉碱甲抑制剂。该策略为早期临床诊断和药物开发提供了一种低成本且方便的方法。