title: Biosensor based on acetylcholinesterase immobilized onto layered double hydroxides for flow injection/amperometric detection of organophosphate pesticides.
abstract: We developed a highly sensitive flow injection/amperometric biosensor for the detection of organophosphate pesticides (OPs) using layered double hydroxides (LDHs) as the immobilization matrix of acetylcholinesterase (AChE). LDHs provided a biocompatible microenvironment to keep the bioactivity of AChE, due to the intrinsic properties of LDHs (such as a regular structure, good mechanical, chemical and thermal stabilities, and swelling properties). By integrating the flow injection analysis (FIA) with amperometric detection, the resulting AChE-LDHs modified electrode greatly catalyzed the oxidation of the enzymatically generated thiocholine product, and facilitated the detection automation, thus increasing the detection sensitivity. The analytical conditions for the FIA/amperometric detection of OPs were optimized by using methyl parathion (MP) as a model. The inhibition of MP was proportional to its concentration ranging from 0.005 to 0.3μg mL(-1) and 0.3 to 4.0μg mL(-1) with a detection limit 0.6ng mL(-1) (S/N=3). The developed biosensor exhibited good reproducibility and acceptable stability.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China. jmgong@mail.ccnu.edu.cn
authors.forename: Jingming
authors.initials: J
authors.lastname: Gong
authors.forename: Zhangqiong
authors.initials: Z
authors.lastname: Guan
authors.forename: Dandan
authors.initials: D
authors.lastname: Song
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D004593:Electrophorus / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D029941:Fish Proteins / Q000737:chemistry / Q000378:metabolism*; D006878:Hydroxides / Q000737:chemistry; D057230:Limit of Detection; D008743:Methyl Parathion / Q000032:analysis* / Q000378:metabolism; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D004800:Enzymes, Immobilized; D029941:Fish Proteins; D006878:Hydroxides; D010575:Pesticides; D008743:Methyl Parathion; D000110:Acetylcholinesterase