N‑Doped Carbon Nanotubes Supported Fe–Mn Dual-Single-Atoms Nanozyme with Synergistically Enhanced Peroxidase Activity for Sensitive Colorimetric Detection of Acetylcholinesterase and Its Inhibitor

• Published in: Analytical chemistry (Washington) Vol. 95; no. 22; pp. 8640 - 8648
• Main Authors: Mao, Yan-Wen, Zhang, Juan, Zhang, Rui, Li, Jia-Qi, Wang, Ai-Jun, Zhou, Xiao-Cheng, Feng, Jiu-Ju
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.06.2023
• Subjects: Acetylcholinesterase; Analytical chemistry; Carbon; Carbon nanotubes; Catalytic oxidation; Chemistry; Colorimetry; Colorimetry - methods; Density functional theory; Diagnosis; Drug development; Electrons; Free radicals; Humans; Huperzine A; Hydrogen peroxide; Hydrogen Peroxide - analysis; Hydroxyl radicals; Inhibitors; Low cost; Manganese; Nanotechnology; Nanotubes; Nanotubes, Carbon; Neurological diseases; Oxidation; Peroxidase; Pyrolysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.3c01070

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.