title: Direct electrochemistry of horseradish peroxidase immobilized on a monolayer modified nanowire array electrode.
abstract: Vertically aligned nanowire array electrodes (NAEs) were prepared by electrodeposition of gold into an anodic aluminium oxide membrane (AAM), providing an ordered three-dimensional (3D) matrix for immobilization of redox proteins. Third-generation H(2)O(2) biosensors were prepared by covalent immobilization of horseradish peroxidase (HRP) on the self-assembled monolayer modified NAEs. Direct electron transfer and electrocatalytic performances of the HRP/NAEs with different nanowire lengths (deposition time of 2, 4 and 5h) were investigated. Results showed that with longer nanowires, better performances were achieved. The HRP/NAE(5h) (5h deposition time) exhibited remarkable sensitivity (45.86 microA mM(-1) cm(-2)) towards H(2)O(2) with a detection limit of 0.42 microM (S/N=3), linearity up to 15 mM and a response time of 4s. The ordered 3D gold nanowire array with high conductivity, excellent electron transfer capability and good biocompatibility proved promising for fabricating sensitive, selective, stable and mediator-free enzymatic biosensors.
authors.affiliation: Tyndall National Institute, University College Cork, Cork, Ireland.
authors.forename: Ju
authors.initials: J
authors.lastname: Xu
authors.forename: Fengjun
authors.initials: F
authors.lastname: Shang
authors.forename: John H T
authors.initials: JH
authors.lastname: Luong
authors.forename: Kafil M
authors.initials: KM
authors.lastname: Razeeb
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Glennon
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D008839:Microelectrodes; D036103:Nanotechnology / Q000295:instrumentation*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase