Study on the Highly Sensitive AChE Electrode Based on Multiwalled Carbon Nanotubes

Using chitosan (CS) as carrier, the method named layer-by-layer (LBL) self-assembly modification to modify the glassy carbon electrode (GCE) with multiwalled carbon nanotubes (MWNTs) and acetylcholine esterase (AChE) was proposed to prepare the acetylcholine esterase electrode with high sensitivity and stability. The modified electrode was used to detect pesticide of aldicarb, and the enzyme inhibition rate of the electrode showed good linearity with pesticide concentrations in the range of 10−10 g·L−1to 10−3 g·L−1. The detection limit was 10−11 g·L−1. The modified electrode was also used to detect the actual sample, and the recovery rate range was from 97.72% to 107.15%, which could meet the rapid testing need of the aldicarb residue. After being stored in the phosphate buffer solution (PBS) in 4°C for 30 days, the modified electrode showed good stability with the response current that was 80% of the original current.