title: Highly-sensitive organophosphorous pesticide biosensors based on nanostructured films of acetylcholinesterase and CdTe quantum dots.
abstract: The optical transducer of CdTe semiconductor quantum dots (QDs) has been integrated with acetylcholinesterase enzyme (AChE) by the layer-by-layer (LbL) assembly technique, resulting in a highly sensitive biosensor for detection of organophosphorus pesticides (OPs) in vegetables and fruits based on enzyme inhibition mechanism. The detection limits of the proposed biosensors are as low as 1.05 × 10(-11) M for paraoxon and 4.47 × 10(-12) M for parathion, which are significantly better than those of the conventional GC/MS methods or amperometric biosensors (0.5 nM). These biosensors are used for quick determination of low concentrations of OPs in real vegetable and fruit samples and exhibit satisfactory reproducibility and accuracy. Moreover, the stock stability of the biosensors are very good due to the stabilizing environment for the enzyme in the nanostructures made by LbL technique. Many advantages provided by these biosensors, like fluorescent change recognized by naked eyes and mass production with low cost, will facilitate future development of rapid and high-throughput screening of OPs.
authors.affiliation: Key Laboratory of Microsystems and Microstructures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Zhaozhu
authors.initials: Z
authors.lastname: Zheng
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Xinyu
authors.initials: X
authors.lastname: Li
authors.forename: Shaoqin
authors.initials: S
authors.lastname: Liu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Tang
mesh_terms: D000110:Acetylcholinesterase; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D019187:Cadmium Compounds; D004800:Enzymes, Immobilized; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000737:chemistry; D055616:Microtechnology; D049329:Nanostructures; D036103:Nanotechnology; D009943:Organophosphorus Compounds / Q000032:analysis*; D010261:Paraoxon / Q000032:analysis; D010278:Parathion / Q000032:analysis; D010575:Pesticides / Q000032:analysis*; D045663:Quantum Dots; D013691:Tellurium; D014675:Vegetables / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D004800:Enzymes, Immobilized; D009943:Organophosphorus Compounds; D010575:Pesticides; D010278:Parathion; D000110:Acetylcholinesterase; D013691:Tellurium; D010261:Paraoxon; C028337:cadmium telluride