All-in-one colorimetric-photothermal-electrochemical platform based on Fe-doped carbon dots nanozyme with enhanced peroxidase-like activity for flexible analysis of acetylcholinesterase

Monitoring acetylcholinesterase (AChE) activity is crucial for the diagnosis of related diseases and drug development. In this study, we present a Fe-doped carbon dots (CDs) nanozyme, N-CD-Fe, with an excellent peroxidase (POD)-like activity, capable of catalyzing the oxidation of 3, 3′, 5, 5′-tetramethylbenzidine (TMB). Hydrolyzing acetylthiocholine by AChE, the resulting product would interact with N-CD-Fe, inhibiting its catalytic activity and affecting TMB oxidation, leading to measurable signal changes. Based on this principle, a tri-mode colorimetric-photothermal-electrochemical platform was constructed to detect AChE activity. This system also enabled visual determination via color changes and heatmaps, providing an intuitive readout. The total cholinesterase in human serum was accurately determined by the developed tri-mode platform, highly consistent with the standard Ellman method. In addition, this platform was applied to screen AChE inhibitors with high reliability. The N-CD-Fe nanozyme-based platform offered a versatile, all-in-one solution for both enzyme biomarker detection and rapid enzyme inhibitor screening, providing a flexible and powerful tool for diagnostic and therapeutic applications. © 2025 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.