Mediator-less highly sensitive voltammetric detection of glutamate using glutamate dehydrogenase/vertically aligned CNTs grown on silicon substrate

Gholizadeh, A ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.bios.2011.10.002
  3. Abstract:
  4. A sensitive glutamate biosensor is prepared based on glutamate dehydrogenase/vertically aligned carbon nanotubes (GLDH, VACNTs). Vertically aligned carbon nanotubes were grown on a silicon substrate by direct current plasma enhanced chemical vapor deposition (DC-PECVD) method. The electrochemical behavior of the synthesized VACNTs was investigated by cyclic voltammetry and electrochemical impedance spectroscopic methods. Glutamate dehydrogenase covalently attached on tip of VACNTs. The electrochemical performance of the electrode for detection of glutamate was investigated by cyclic and differential pulse voltammetry. Differential pulse voltammetric determinations of glutamate are performed in mediator-less condition and also, in the presence of 1 and 5μM thionine as electron mediator. The linear calibration curve of the concentration of glutamate versus peak current is investigated in a wide range of 0.1-500μM. The mediator-less biosensor has a low detection limit of 57nM and two linear ranges of 0.1-20μM with a sensitivity of 0.976mAmM -1cm -2 and 20-300μM with a sensitivity of 0.182mAmM -1cm -2. In the presence of 1μM thionine as an electron mediator, the prepared biosensor shows a low detection limit of 68nM and two linear ranges of 0.1-20 with a calibration sensitivity of 1.17mAmM -1cm -2 and 20-500μM with a sensitivity of 0.153mAmM -1cm -2. The effects of the other biological compounds on the voltammetric behavior of the prepared biosensor and its response stability are investigated. The results are demonstrated that the GLDH/VACNTs electrode even without electron mediator is a suitable basic electrode for detection of glutamate
  5. Keywords:
  6. Glutamate ; Vertically aligned carbon nanotubes ; Aligned carbon nanotubes ; Aligned CNTs ; Biological compounds ; Chemical vapor ; Differential pulse ; Electrochemical behaviors ; Electrochemical impedance ; Electrochemical performance ; Electron mediator ; Glutamate biosensor ; Highly sensitive ; Linear calibration curve ; Linear range ; Low detection limit ; Mediator-less ; Peak currents ; Response stability ; Silicon substrates ; Spectroscopic method ; Vertically aligned carbon nanotube ; Voltammetric behaviors ; Voltammetric detection ; Voltammetric determination ; Biosensors ; Carbon ; Carbon nanotubes ; Chemical detection ; Chemical vapor deposition ; Electrochemical electrodes ; Plasma deposition ; Plasma enhanced chemical vapor deposition ; Spectroscopic analysis ; Voltammetry ; Cyclic voltammetry ; carbon nanotube ; Silicon ; Thionine ; Biosensor ; Calibration ; Chemical procedures ; Concentration (parameters) ; Controlled study ; Covalent bond ; Cyclic potentiometry ; Differential pulse voltammetry ; Direct current plasma enhanced chemcial vapor deposition ; Electrochemical impedance spectroscopy ; Electrode ; Enzyme immobilization ; Limit of detection ; Biosensing Techniques ; Conductometry ; Enzymes, Immobilized ; Equipment Design ; Equipment Failure Analysis ; Glutamate Dehydrogenase ; Glutamic Acid ; Nanotechnology ; Nanotubes, Carbon ; Reproducibility of Results ; Sensitivity and Specificity
  7. Source: Biosensors and Bioelectronics ; Volume 31, Issue 1 , 2012 , Pages 110-115 ; 09565663 (ISSN)
  8. URL: http://www.sciencedirect.com/science/article/pii/S0956566311006695