Electrochemical acetylcholinesterase biosensor based on multi-walled carbon nanotubes/dicyclohexyl phthalate modified screen-printed electrode for detection of chlorpyrifos

Abstract A biosensor based on dicyclohexyl phthalate (DCHP) and multi-walled carbon nanotubes (MWCNTs) modified a screen-printed electrode (SPE) has been developed for detection of chlorpyrifos. Compared with a common electrode, a SPE exhibited advantageous material properties which can be applied to the in situ detection. Herein, the fabricated biosensor was developed based on the nanocomposites of DCHP and MWCNTs modified a screen-printed electrode. This strategy enhanced electron transfer rate at a lower potential and catalyzed electrochemical oxidation of acetylthiocholine effectively. Acetylcholinesterase (AChE) was immobilized onto the nanocomposites film to prepare an AChE biosensor for pesticide residues detection. Moreover, the biosensor had also been successfully employed for the determination of pesticide with low concentrations in real vegetable samples. Based on the inhibition of pesticide on the AChE activity, chlorpyrifos used as model compounds, this biosensor showed a wide range, low detection limit, good reproducibility and high stability. The inhibition of chlorpyrifos was proportional to its concentration ranging from 0.05 to 1.0 × 10 5  μg/L with a detection limit of 0.05 μg/L. The developed biosensor exhibited a good reproducibility and acceptable stability.