title: Highly-sensitive organophosphorus pesticide biosensors based on CdTe quantum dots and bi-enzyme immobilized eggshell membranes.
abstract: An optical biosensing method using CdTe quantum dots (QDs) and bi-enzyme-immobilized eggshell membranes for the determination of organophosphorus pesticides (OPs) has been developed. Increasing amounts of OPs led to a decrease of the enzymatic activity and thus a decrease in the production of hydrogen peroxide (H2O2), which can quench the fluorescence of the CdTe QDs. Under the optimum conditions, there was a good linear relationship between the enzyme inhibition percentage and the logarithm of paraoxon or parathion concentration in the range of 1.0 × 10(-11)-1.0 × 10(-6) mol L(-1). The detection limit (S/N = 3) of the proposed biosensors were as low as 4.30 × 10(-12) mol L(-1) for paraoxon and 2.47 × 10(-12) mol L(-1) for parathion. The bi-enzyme-immobilized eggshell membrane demonstrated a long shelf-life of at least 2 months and the results showed good repeatability. The proposed method was successfully applied to the determination of the OPs in real fruit samples with satisfactory results.
authors.affiliation: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Food Safety Key Lab of Liaoning Province, National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, Liaoning 121013, China. huaxue_gaoxue@126.com lijr6491@163.com.
authors.forename: Gao
authors.initials: G
authors.lastname: Xue
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yue
authors.forename: Zhang
authors.initials: Z
authors.lastname: Bing
authors.forename: Tang
authors.initials: T
authors.lastname: Yiwei
authors.forename: Liu
authors.initials: L
authors.lastname: Xiuying
authors.forename: Li
authors.initials: L
authors.lastname: Jianrong
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry*; D004528:Egg Shell; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D005638:Fruit / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D057230:Limit of Detection; D008163:Luminescent Measurements; D008566:Membranes / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis; D045663:Quantum Dots / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D004800:Enzymes, Immobilized; D009943:Organophosphorus Compounds; D010575:Pesticides; D006861:Hydrogen Peroxide; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D000110:Acetylcholinesterase; D013691:Tellurium; C028337:cadmium telluride