Fabrication of a modified electrode based on Fe3 O4 NPs/MWCNT nanocomposite: Application to simultaneous determination of guanine and adenine in DNA

Shahrokhian, S ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.bioelechem.2012.02.004
  3. Abstract:
  4. Multi-walled carbon nanotubes decorated with Fe 3O 4 nanoparticles (Fe 3O 4NPs/MWCNT) were prepared and used to construct a novel biosensor for the simultaneous detection of adenine and guanine. The direct electro-oxidation of adenine and guanine on the modified electrode were investigated by linear sweep voltammetry. The results indicate a remarkable increase in the oxidation peak currents together with negative shift in the oxidation peak potentials for both adenine and guanine, in comparison to the bare glassy carbon electrode (GCE). The surface morphology and nature of the composite film deposited on GCE were characterized by transmission electron microscopy, atomic force microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The Fe 3O 4NPs/MWCNT based electrochemical biosensor exhibits linear ranges of 0.01-10μM and 0.05-8μM with detection limits of 1nM and 5nM for adenine and guanine, respectively. The proposed method was successfully applied for a highly sensitive simultaneous determination of trace amounts of adenine and guanine in DNA of fish sperm samples with satisfactory results. The experimental detection limit was found to be equal to 3ngmL -1 DNA. The value of (G+C)/(A+T) in DNA was calculated to be 0.81. The fabricated electrode showed excellent reproducibility, repeatability and stability
  5. Keywords:
  6. Adenine ; Fe3O4 nanoparticles ; Guanine ; Multi-walled carbon nanotube ; Voltammetry ; Detection limits ; Electrochemical biosensor ; Glassy carbon electrodes ; Highly sensitive ; Linear range ; Linear sweep voltammetry ; Modified electrodes ; Negative shift ; Oxidation peak ; Reproducibilities ; Simultaneous detection ; Simultaneous determinations ; Trace amounts ; Atomic force microscopy ; Biosensors ; Composite films ; Cyclic voltammetry ; DNA ; Electrochemical impedance spectroscopy ; Multiwalled carbon nanotubes (MWCN) ; Nanoparticles ; Oxidation ; Positive ions ; Transmission electron microscopy ; Glass membrane electrodes ; Multi walled nanotube ; Nanocomposite ; Biosensor ; Chemical modification ; Cyclic potentiometry ; Electric current ; Electrode ; Nanofabrication ; Biosensing techniques ; Calibration ; Dielectric spectroscopy ; Electrochemical techniques ; Electrodes ; Ferric compounds ; Fishes ; Hydrogen-ion concentration ; Limit of detection ; Magnetite nanoparticles ; Male ; Microscopy, atomic force ; Microscopy, electron, transmission ; Nanocomposites ; Nanotubes, carbon ; Oxidation-reduction ; Reproducibility of results ; Spermatozoa ; Surface properties
  7. Source: Bioelectrochemistry ; Volume 86 , 2012 , Pages 78-86 ; 15675394 (ISSN)
  8. URL: http://www.sciencedirect.com/science/article/pii/S1567539412000394