LAUSR

A simple, low cost and sensitive electrochemical biosensor was developed for detection of chlorpyrifos, based on an acetylcholinesterase/multi-walled carbon nanotubes/ionic liquid composite modified screen-printed electrode (AChE/MWCNTs/IL/SPE). In this study, incorporating MWCNTs and IL formed a relative uniform microarchitecture on the electrode surface to promote electron transfer and enhance electrochemical response, hence, the fabricated biosensor exhibited obvious electrochemical signal in the redox probe [Fe(CN)6] 3−/4− during the detection. AChE as a biorecognition element was immobilized onto the successfully modified SPE, which enabled sensitive determination of chlorpyrifos owing to high affinity of organophosphate pesticides toward the AChE. The morphologies and electrochemistry behaviors of AChE/MWCNTs/IL/SPE were investigated by using cyclic voltammetry (CV) and scanning electron microscopy (SEM), respectively. Under optimal conditions, chlorpyrifos could be detected in the wide linear range of 0.05 -1.0×10 5 μg/L with a detection limit of 0.05 μg/L. The biosensor also showed other advantages such as convenient preparation, good reproducibility, excellent stability and high sensitive. Moreover, the biosensor could also be used for directly analysis of real vegetable samples, which would provide a new promising tool for pesticide residues tests.