title: Nanostructured photoelectrochemical biosensor for highly sensitive detection of organophosphorous pesticides.
abstract: A sensitive photoelectrochemical (PEC) biosensor for detection of organophosphorus pesticides (OPs) using the nanocomposite of CdSe@ZnS quantum dots (QDs) and graphene deposited on the ITO coated glass electrode as a photoactive electrode is presented. The integration of CdSe@ZnS/graphene nanocomposite with biomolecules acetylcholinesterase (AChE) as a biorecognition element yields a novel biosensing platform. Under visible light irradiation, the AChE-CdSe@ZnS/graphene nanocomposite can generate a stable photocurrent and the photocurrent is found to be inversely dependent on the concentration of OPs. Under the optimal experimental conditions, the photocurrents were proportional to the logarithm of paraoxon and dichlorvos within the concentration range of 10(-12)-10(-6) M. The detection limits (LOD) of the proposed biosensor for paraoxon and dichlorvos are as low as 10(-14) M and 10(-12) M. The photoelectrochemical biosensor shows good sensitivity, reproducibility, stability, and could be successfully applied to detection of OPs in real fruit samples.
authors.affiliation: Key Laboratory of Microsystems and Microstructures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China; School of Life Science and Technology, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Microsystems and Microstructures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China; School of Life Science and Technology, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Zhaozhu
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Microsystems and Microstructures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Shenlong
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Microsystems and Microstructures Manufacturing, Ministry of Education, Harbin Institute of Technology, Harbin 150080, China. Electronic address: shaoqinliu@hit.edu.cn.
authors.forename: Shaoqin
authors.initials: S
authors.lastname: Liu
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000378:metabolism; D005638:Fruit / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D008027:Light; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000378:metabolism; D010261:Paraoxon / Q000032:analysis; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D045663:Quantum Dots / Q000737:chemistry; D015203:Reproducibility of Results; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D004800:Enzymes, Immobilized; D009943:Organophosphorus Compounds; D010575:Pesticides; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D006108:Graphite; C058667:cadmium selenide; D000110:Acetylcholinesterase; C031238:zinc sulfide; D010261:Paraoxon
keywords: AChE; Graphene; Organophosphorus pesticides; Photoelectrochemical biosensor; Quantum dots