Bismuth atom-doped gold aerogels for the detection of acetylcholinesterase activity and organophosphorus inhibitor

Monitoring acetylcholinesterase activity and its organophosphorus inhibitor is crucial for ecological health and food safety. However, current quantification techniques typically require significant financial, equipment, and human resources, restricting further practical use and popularization. Herein, Au aerogels/hydrogels with the atomic-scale dispersed bismuth (Bi0.01Au1 nanozymes) were proposed with high peroxidase-like activity and utilized to develop a simple and reliable colorimetric sensing platform. The introduction of Bi atoms at the atomic scale led to a more than 10-fold improvement in peroxidase-like activity compared to pure Au aerogels, which is beneficial for ensuring high sensitivity in the sensing platform. Notably, we developed a simple and reliable Bi0.01Au1 nanozyme-based colorimetric sensing platform to assess acetylcholinesterase activity, achieving a low limit of detection of 0.021 mU mL−1, which is better than most reported methods. Based on the cascade amplification, taking paraoxon-ethyl as a typical pesticide, a biosensor integrating Bi0.01Au1 nanozymes and acetylcholinesterase was established to detect the organophosphorus inhibitor of acetylcholinesterase, which show high sensitivity, anti-interference capacity, and satisfactory recoveries. This work presents an efficient strategy for constructing high-performance nanozymes at the atomic scale, which can inspire the development of nanozyme-based biosensing platforms for monitoring acetylcholinesterase activity and its organophosphorus inhibitors.