Au-Decorated N‑Rich Carbon Dots as Peroxidase Mimics for the Detection of Acetylcholinesterase Activity

Well-distributed metals anchored on supports have attracted great attention owing to their potential application as cost-effective catalysts. Here, we demonstrate the successful preparation of Au-decorated N-rich carbon dot (Au-CD) nanocomposites, which possess excellent stability in aqueous media. The Au-CDs exhibit remarkable peroxidase-mimicking activity and high affinity to the substrate due to the fast electron-transfer process and ligand-free surface. Based on this, an Au-CD nanozyme-based colorimetric biosensor was successfully developed to assess the activity of acetylcholinesterase with high sensitivity and selectivity. More importantly, an ideal performance was achieved in clinical serum analysis. This work paves the way for the development of well-distributed metals anchored on supports as nanozymes for sensing applications.