title: Evaluation of a carbon nanotube-titanate nanotube nanocomposite as an electrochemical biosensor scaffold.
abstract: A significant aspect of this work is the development of a multi-wall carbon nanotube (MWCNT)-titanate nanotube (TNT) nanocomposite to serve as a biocompatible scaffold with high conductivity on a biosensor surface. Unlike other scaffolds consisting of MWCNTs alone or TNTs alone, the MWCNT-TNT nanocomposite synergistically provides excellent biocompatibility, good electrical conductivity, low electrochemical interferences and a high signal-to-noise ratio. For comparison, after characterising a scaffold consisting of MWCNTs alone, TNTs alone and a MWCNT-TNT nanocomposite using several spectroscopic techniques, the analytical performance of a horseradish peroxidase (HRP) electrochemical biosensor was evaluated using cyclic voltammetry and differential pulse voltammetry. The scaffold consisting of MWCNTs alone displayed a high background charging current, a low signal-to-noise ratio and distinct electrochemical interference from its surface functional groups. In contrast, the direct electrochemistry and the catalytic capability of HRP at MWCNT-TNT modified biosensors towards H2O2 was demonstrated to be ~51% and ~144% enhanced, respectively, compared to those at TNT modified biosensors. Meanwhile, MWCNT-TNT nanocomposite modified HRP biosensors also exhibited higher sensitivity (4.42μAmM(-1)) than TNT modified HRP biosensors (1.48μAmM(-1)). The above superior performance was attributed to the improved properties of MWCNT-TNT nanocomposite as biosensor scaffold compared to its two individual components by complementing each component and synergistically sustaining the characteristic features of each component.
authors.affiliation: Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan Province 475004, PR China. Electronic address: xq_liu1975@yahoo.com.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan Province 475004, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yan
authors.affiliation: Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan Province 475004, PR China.
authors.forename: Jiamei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan Province 475004, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia. Electronic address: Danny.Wong@mq.edu.au.
authors.forename: Danny K Y
authors.initials: DK
authors.lastname: Wong
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004563:Electrochemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D059629:Signal-To-Noise Ratio; D014303:Trinitrotoluene / Q000737:chemistry
chemical_list: D037742:Nanotubes, Carbon; D014303:Trinitrotoluene; D006861:Hydrogen Peroxide
keywords: Catalytic capability; Direct electrochemistry; Electrochemical biosensor; Immobilisation materials; MWCNT–TNT nanocomposites