Research On Acetylcholinesterase Biosensor Based On Screen-printed Electrodes

The pesticide residues detection technology, which is quick and accurate, is an effective approach to ensure the safety of agricultural products. To solve the above problems, this paper intended to provid the theoretical foundation for the analysis between acetylcholinesterase and organophosphate pesticides, owing to the screen-printed electrodes’ s advantages of low cost, simplicity, and convenience. The pesticide residues detection method was constructed, in which the screen-printed electrodes serves as reaction platform and the ACh E biosensor acts as the detector, respectively.In this study, three kinds of ACh E biosensor were developed based on synergistic modification of different nanomaterials for pesticide residues detection.1. Acetylcholinesterase biosensor based on ionic liquid/multi-walled carbon nanotubes(IL-MWCNTs) nanocompositeThe IL-MWCNTs nanocomposite had high conductivity, good electrochemical activity and strong chemical stability. IL-MWCNTs nanocomposite provided a good interface for acetylcholinesterase immobilization and maintained the activity of acetylcholinesterase to sustain the effective binding with chlorpyrifos. Based on the inhibition of pesticides on the acetylcholinesterase activity, using chlorpyrifos as model pesticide, the proposed biosensor exhibited a wide range, low detection limit.2. Acetylcholinesterase biosensor based on dicyclohexyl phthalate/multi-walled carbon nanotubes(DCHP-MWCNTs) nanocompositeThe synergistic effects of DCHP, MWCNTs could highly enhance the electrochemical response and improved the sensitivity of biosensor. The DCHP-MWCNTs nanocomposite showed good electrochemical performance. Under optimized conditions, using chlorpyrifos as the model compound, the results showed that the inhibitory effect of chlorpyrifos was proportional to its concentration ranging from 0.05 to 1×105 μg/L in different slopes.3. Acetylcholinesterase biosensor based on multi-walled carbon nanotubes-Sn O2-chitosan(MWCNTs-Sn O2-CHIT) nanocompositeThe MWCNTs-Sn O2-CHIT had good biocompatibility and good electrochemical redox properties. The morphologies and electrochemistry properties of the surface modification were investigated by using scanning electron microscopy(SEM), cyclic voltammetry(CV) and differential pulse voltammetry(DPV), respectively. The proposed method was proven to be a feasible quantitative method for chlorpyrifos analysis, which may open a new door ultrasensitive detection of chlorpyrifos residues in vegetables and fruits.Comparing the performance of above three kind of ACh E biosensors, the resuluts showed that the ACh E biosensor based on MWCNTs-Sn O2-CHIT/SPE present wider detection, range lower limit, and more outstanding stability and reproducibility.