Constructing self-assembled nanohybrids for the ratiometric fluorescent sensing of acetylcholinesterase activity

The dysfunction of acetylcholinesterase (AChE) activity is responsible for many complex nervous diseases, demonstrating the urgent demand of constructing assays with robust performance for determining AChE activity. Herein, a ratiometric fluorescent (RF) sensing platform for AChE activity was strategically fabricated, which was based on the self-assembly of Ag+-modified Au nanoclusters and silicon nanoparticles (Ag-AuNCs@SiNPs) nanohybrids to perform as the RF probes. The Ag-AuNCs@SiNPs nanohybrids were facilely prepared through the electrostatic attraction between positively charged SiNPs and negatively charged Ag-AuNCs. AChE can catalyze the hydrolysis of ATCh into thiocholine (TCh) that in turn quenched the fluorescence of Ag-AuNCs in the Ag-AuNCs@SiNPs nanohybrids. Meanwhile, the fluorescence emission intensity of SiNPs remained stable. Consequently, based on the change of RF signal, AChE activity was sensitively detected in the range of 0.03-4.0 U/L with a low detection limit of 0.0021 U/L. This RF strategy was applied for AChE activity sensing in human serum sample with reliable performance, indicating the vast application prospect of this assay for the AChE-related clinical investigation.

Automated summary

The study developed a ratiometric fluorescent sensing platform based on Ag-AuNCs@SiNPs nanohybrids for detecting AChE activity, which showed high sensitivity and stability, making it suitable for reliable detection of AChE activity in human serum samples.