摘要

A novel acetylcholinesterase (AChE) biosensor was developed based on layer-by-layer assembly of chitosan (CS), gold nanoparticles (GNPs), AChE and Nafion (NF) modified nano-porous pseudo carbon paste electrode (nano-PPCPE). The proposed biosensor exhibited a high affinity to the substrate of AChE and produced a detectable and fast response owing to its excellent electron transfer rate and satisfactory biocompatibility of GNPs/CS. Nano-PPCPE displayed good electrode chemical behavior, low detection limit and good stability. Nafion (NF) was used as a protective membrane of the AChE biosensor. The AChE biosensor showed favorable affinity to acetylthiocholine iodide (ATChI) with wide linear range (1.0 x 10(-4)-1.0 x 10(-7) M) and an ultralow detection limit of 1.0 x 10(-8) M. Under optimum conditions, the biosensor detected methyl parathion in the linear range from 1.0 x 10(-8) to 1.0 x 10(-14) g/mL with a detection limit of 5,0 x 10(-15) g/mL. The proposed biosensor exhibited good sensitivity, stability, and reproducibility, thus providing a promising analytical tool for pesticide detection.