title: Facile hydrothermal growth graphene/ZnO nanocomposite for development of enhanced biosensor.
abstract: Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) in a linear range of 1-15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 μAmM(-1) with a limit of detection of 7.4357 μM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P < 0.05) and efficient than the conventional agarose gel electrophoresis.
authors.affiliation: Department of Electrical and Electronic Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia; Division of Materials, Mechanics and Structures, Center of Nanotechnology and Advanced Materials, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
authors.forename: Sze Shin
authors.initials: SS
authors.lastname: Low
authors.affiliation: Department of Electrical and Electronic Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia; Division of Materials, Mechanics and Structures, Center of Nanotechnology and Advanced Materials, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia. Electronic address: Michelle.Tan@nottingham.edu.my.
authors.forename: Michelle T T
authors.initials: MT
authors.lastname: Tan
authors.affiliation: School of Biosciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia; Biotechnology Research Centre, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
authors.forename: Hwei-San
authors.initials: HS
authors.lastname: Loh
authors.affiliation: Division of Materials, Mechanics and Structures, Center of Nanotechnology and Advanced Materials, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
authors.forename: Poi Sim
authors.initials: PS
authors.lastname: Khiew
authors.affiliation: Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Wee Siong
authors.initials: WS
authors.lastname: Chiu
mesh_terms: D015374:Biosensing Techniques; D006108:Graphite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D006108:Graphite; D015034:Zinc Oxide
keywords: Avian influenza virus H5N1; Electrochemical DNA biosensor; Graphene/zinc oxide nanocomposite; Green approach; Hydrogen peroxide; Screen printed carbon electrode