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Ionic liquid/graphene oxide as a nanocomposite for improving the direct electrochemistry and electrocatalytic activity of glucose oxidase

Tasviri, M ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.1007/s10008-012-1858-5
  3. Publisher: 2013
  4. Abstract:
  5. By combination of 1-ethyl-3-methyl immidazolium ethyl sulfate as a typical room temperature ionic liquid (IL) and graphene oxide (GO) nanosheets, a nanocomposite was introduced for improving the direct electrochemistry and electrocatalytic activity of glucose oxidase (GOx). The enzyme on the IL-GO-modified glassy carbon electrode exhibited a quasireversible cyclic voltammogram corresponding to the flavine adenine dinucleotide/FADH2 redox prosthetic group of GOx. At the scan rate of 100 mV s-1, the enzyme showed a peak-to-peak potential separation of 82 mV and the formal potential of -463 mV (vs Ag/AgCl in 0.1 M phosphate buffer solution, pH 7.0). The kinetic parameters of the charge transfer rate constant, the electron transfer coefficient, and the apparent Michaelis-Menten constant were calculated as 1.36 s-1 and 0.35 and 2.47 μM, respectively. When the modified electrode was examined as a biosensor for glucose determination, a linear range of 2.5-45 nM with detection limit of 0.175 nM (signal to noise = 3) was obtained. The biosensor was stable for 2 months
  6. Keywords:
  7. Biosensor ; Graphene oxide ; Ionic liquid ; Ag/AgCl ; Charge-transfer rate ; Cyclic voltammograms ; Detection limits ; Dinucleotides ; Direct electrochemistry ; Electrocatalytic activity ; Electron transfer coefficient ; Ethyl sulfate ; Formal potential ; Glassy carbon electrodes ; Glucose determination ; Graphene oxides ; Linear range ; Michaelis-Menten constant ; Modified electrodes ; Peak-to-peak ; Phosphate buffer solutions ; Prosthetic groups ; Room temperature ionic liquids ; Scan rates ; Signal to noise ; Biosensors ; Charge transfer ; Enzymes ; Glass membrane electrodes ; Glucose ; Glucose oxidase ; Glucose sensors ; Ionic liquids ; Nanocomposites ; Rate constants ; Electrochemistry
  8. Source: Journal of Solid State Electrochemistry ; Volume 17, Issue 1 , January , 2013 , Pages 183-189 ; 14328488 (ISSN)
  9. URL: http://link.springer.com/article/10.1007%2Fs10008-012-1858-5