title: Sensitive electrochemical immunoassay for chlorpyrifos by using flake-like Fe3O4 modified carbon nanotubes as the enhanced multienzyme label.
abstract: A highly sensitive electrochemical immunoassay of chlorpyrifos (CPF) was developed by using a biocompatible quinone-rich polydopamine nanospheres modified glass carbon electrode as the sensor platform and multi-horseradish peroxidase-flake like Fe3O4 coated carbon nanotube nanocomposites as the signal label. Due to the quinone-rich polydopamine nanospheres, the platform exhibited excellent fixing capacity by simple coating of sticky polydopamine nanospheres and subsequent oxidization. By coprecipitation of Fe(3+) and Fe(2+) on polydopamine modified carbon nanotubes (CNTs) with the aid of ethylene glycol (EG), the flake-like Fe3O4 coated CNTs (CNTs@f-Fe3O4) were synthesized and chosen as the carrier of multi-enzyme label due to the high loading of secondary antibody (Ab2) and horseradish peroxidase (HRP) and also the peroxidase-mimic activity of Fe3O4. Under the optimum conditions, the immunosensor can detect CPF over a wide range with a detection limit of 6.3 pg/mL. Besides, the high specificity, reproducibility and stability of the proposed immunosensor were also proved. The preliminary application in real sample showed good recoveries, indicating it holds promise for fast analysis of CPF in aquatic environment.
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Zihong
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Xinjiang Production & Construction Group, Key Laboratory of Agricultural Products in Xinjiang South, Tarim University, Alar 843300, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Wang
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Haibin
authors.initials: H
authors.lastname: Wen
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Cuifen
authors.initials: C
authors.lastname: Gan
authors.affiliation: The Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Lei
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China. Electronic address: liuyingju@hotmail.com.
authors.forename: Yingju
authors.initials: Y
authors.lastname: Liu
mesh_terms: D004390:Chlorpyrifos / Q000032:analysis*; D007118:Immunoassay / Q000379:methods*; D007306:Insecticides / Q000032:analysis*; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission
chemical_list: D007306:Insecticides; D004390:Chlorpyrifos
keywords: Carbon nanotubes; Chlorpyrifos; Electrochemical immunosensor; Fe(3)O(4); Polydopamine nanospheres