title: Controlled immobilization of acetylcholinesterase on improved hydrophobic gold nanoparticle/Prussian blue modified surface for ultra-trace organophosphate pesticide detection.
abstract: An ultrasensitive amperometric acetylcholinesterase (AChE) biosensor was fabricated by controlled immobilization of AChE on gold nanoparticles/poly(dimethyldiallylammonium chloride) protected Prussian blue (Au-PDDA-PB) nanocomposite modified electrode surface for the detection of organophorous pesticide. The Au-PDDA-PB membrane served as an excellent matrix for the immobilization of enzyme, which not only enhanced electron transfer but also possessed a relatively large surface area. In addition, the surface hydrophilicity of the Au-PDDA-PB nanocomposite was finely controlled in the static water contact angle range of 25.6-78.1° by adjusting the ratio of gold nanoparticles to PDDA-PB. On an optimized hydrophobic surface, the AChE adopts an orientation with both good activity and stability, which has been proven by electrochemical methods. Benefit from the advantages of the Au-PDDA-PB nanocomposite and the good activity and stability of AChE, the biosensor shows significantly improved sensitivity to monocrotophos, a typical highly toxic organophorous pesticide, with wide linear range (1.0-1000 pg/mL and 1.0-10 ng/mL) and an ultra-low detection limit of 0.8 pg/mL. The biosensor exhibits accuracy, good reproducibility and stability. This strategy may therefore provide useful information for the controlled immobilization of protein and the design of highly sensitive biosensors.
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian, PR China. wushuo@dlut.edu.cn
authors.forename: Shuo
authors.initials: S
authors.lastname: Wu
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Lan
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Yuping
authors.initials: Y
authors.lastname: Li
authors.forename: Lihui
authors.initials: L
authors.lastname: Zhang
authors.forename: Hainan
authors.initials: H
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Han
authors.forename: Shengyang
authors.initials: S
authors.lastname: Tao
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry*; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005295:Ferrocyanides / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008999:Monocrotophos / Q000032:analysis; D010755:Organophosphates / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D005295:Ferrocyanides; D010755:Organophosphates; D010575:Pesticides; D014867:Water; D008999:Monocrotophos; D006046:Gold; D000110:Acetylcholinesterase; C000170:ferric ferrocyanide