Novel electrochemical biosensor based on core-shell nanostructured composite of hollow carbon spheres and polyaniline for sensitively detecting malathion

摘要

Graphical abstractA novel core-shell nanocomposite of hollow carbon spheres coated with needle-like polyaniline (denoted by HCS@PANI) was prepared and used for rapid determination of malathion. The fabricated electrochemical biosensor showed high sensitivity and low detection limit of 0.16pgmL−1within a linear range from 1.0ngmL−1to 10μgmL−1of the malathion concentration, as well as high selectivity, acceptable stability, and good reproducibility.Display OmittedHighlights•Hollow carbon spheres@polyaniline core-shell nanocomposite (HCS@PANI) was prepared.•HCS@PANI was anchored with AChE to construct electrochemical inhibition biosensor.•Low detection limit and wide linear range of malathion were obtained.•High selectivity, stability, and applicability of the electrochemical biosensor.AbstractA novel electrochemical biosensor was constructed by anchoring acetylcholine esterase (AChE) onto the core-shell nanostructured composite of hollow carbon spheres coated with needle-like polyaniline (denoted by HCS@PANI), and used for rapid determination of malathion, which was established based on the chemisorption/desorption process of AChE used as an indicator. The uniformly distributed HCS was wrapped with the needle-like PANI nanowires to form the HCS@PANI nanocomposite, which not only exhibits high specific surface area and chemical functionality but also possesses strong electrochemical activity. After AChE was adsorbed onto the HCS@PANI nanocomposite, the electrochemical catalysis of AChE/HCS@PANI-based biosensor towards acetylthiocholine chloride (ATCl) was inhibited in the presence of malathion, which was applied to detect malathion, and the biosensor exhibited a low detection limit of 0.16ngmL−1within a linear range from 1.0ngmL−1to 10μgmL−1of the malathion concentration. Also, the results suggested that the developed electrochemical biosensor showed high selectivity, good reproducibility, and applicability for malathion detection, indicating that the proposed method using the HCS@PANI nanocomposite as the sensitive layer for the AChE immobilization and catalysis of ATCl has potential application in high-sensitive pesticide determinations.