Electrodeposited chitosan-calcium carbonate-gold nanoparticles composite film based biosensor for organophosphorous pesticide.

Objective To develop a novel biosensor based on chitosan-calcium carbonate-gold nanoparticles composite film immobilizing acetylcholinesterase Methods The chitosan,calcium carbonate and gold nanoparticles were one-step electrodeposited onto a glassy carbon electrode.Due to the bubble generated in the electrodeposit process,the generated micro-CaCO3-based matrix showed a three-dimensional porous structure,providing a favorable and biocompatible micro-environment to dispersedly immobilize enzyme onto it and improve the detection effect.With the introduction of gold nanoparticles,the signal was amplified and the transmission of electrons was accelerated.Results The prepared biosensor showed a favorable electrochemical behavior with a detection limit of 2.5 pg/mL and detection time of 7 min for dimethoate.Conclusion The established method is ultrasensitive and rapid,and can be used to detect organophosphorous pesticide.