title: Shape-dependent electron transfer kinetics and catalytic activity of NiO nanoparticles immobilized onto DNA modified electrode: fabrication of highly sensitive enzymeless glucose sensor.
abstract: Herein we describe improved electron transfer properties and catalytic activity of nickel oxide nanoparticles (NiONPs) via the electrochemical deposition on DNA modified glassy carbon electrode (DNA/GCE) surface. NiONPs deposited on the bare and DNA-coated GCE showed different morphologies, electrochemical kinetics and catalytic activities. The atomic force microscopy (AFM) images revealed the formation of triangular NPs on the DNA/GCE that followed the shape produced by the DNA template, while the electrodeposition of NiONPs on the bare GCE surface led to the formation of spherical nanoparticles. Electrochemical impedance spectroscopy (EIS) measurements revealed lower charge-transfer resistance (Rct) of triangular NiONPs compared to spherical NPs. Furthermore, the electrocatalytic activity of triangular NiONPs compared to spherical NPs toward glucose oxidation in alkaline media was significantly improved. The amperometric oxidation of glucose at NiONP-DNA/GCE, yielded a very high sensitivity of 17.32 mA mM(-1)cm(-2) and an unprecedented detection limit of 17 nM. The enhanced electron transfer properties and electrocatalytic activity of NiONP-DNA/GCE can be attributed to the higher fraction of sharp corners and edges present in the triangular NiONPs compared to the spherical NPs. The developed sensor was successfully applied to the determination of glucose in serum samples.
authors: Chemistry Department, University of Isfahan, Hezar Jarib, Isfahan 81746-73441, Iran.
authors: Ensiyeh
authors: E
authors: Sharifi
authors: Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj, Iran; Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj, Iran. Electronic address: absalimi@uok.ac.ir.
authors: Abdollah
authors: A
authors: Salimi
authors: Chemistry Department, University of Isfahan, Hezar Jarib, Isfahan 81746-73441, Iran. Electronic address: e_shams@chem.ui.ac.ir.
authors: Esmaeil
authors: E
authors: Shams
authors: Department of Nanotechnology Engineering, Faculty of Advanced Science and Technology, University of Isfahan, Hezar Jarib, Isfahan 81746-73441, Iran.
authors: Abdollah
authors: A
authors: Noorbakhsh
authors: Chemistry Department, University of Isfahan, Hezar Jarib, Isfahan 81746-73441, Iran.
authors: Mohammad K
authors: MK
authors: Amini
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis*; D002384:Catalysis; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D004566:Electrodes; D004579:Electron Transport; D004595:Electroplating; D006801:Humans; D007700:Kinetics; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009532:Nickel / Q000737:chemistry*
chemical_list: D001786:Blood Glucose; D009532:Nickel; D004247:DNA; C028007:nickel monoxide
keywords: DNA; Enzymeless biosensor; Glucose; Nickel oxide; Triangular nanoparticles