Zhou_2024_Food.Chem_441_138372

Herein, we synthesized a novel N-doped carbon layer encapsulated Fe/Co bimetallic nanoparticles (Fe/Co-NC), which exhibited superior oxidase-like activity due to the facilitation of electron penetration and the formation of metal-nitrogen active sites. Fe/Co-NC could catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) to blue oxTMB. Acetylcholinesterase (AChE) could catalyze the hydrolysis of thioacetylcholine to produce reducing thiocholine, which prevented TMB from oxidation. Thus, a portable hydrogel colorimetric sensor was developed for on-site and visual monitoring of AChE with the detection limit of 0.36 U L(-1), and successfully applied to detect AChE in human erythrocyte samples. Furthermore, this platform was used to investigate the inhibition of triazophos on AChE activity.