Selective voltammetric determination of d-penicillamine in the presence of tryptophan at a modified carbon paste electrode incorporating TiO2 nanoparticles and quinizarine

Mazloum Ardakani, M ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jelechem.2010.02.034
  3. Publisher: 2010
  4. Abstract:
  5. A carbon paste electrode (CPE) chemically modified with TiO2 nanoparticles and quinizarine (QZ) was used as a selective electrochemical sensor for the simultaneous determination of minor amounts of d-penicillamine (D-PA) and tryptophan (Trp). This modified electrode showed very efficient electrocatalytic activity for anodic oxidation of both d-PA and Trp. Substantial decreases of anodic overpotentials for both compounds made this analysis possible. Results of square wave voltammetry (SWV) using this modified electrode showed two well-resolved anodic waves for the oxidation of d-PA and Trp, which makes the simultaneous determination of both compounds possible. The peak potential for the oxidation of d-PA was lowered by at least 220 mV compared with that obtained for an unmodified CPE. In optimal conditions, linear ranges spanned a d-PA concentration from 0.8 μM to 140.0 μM and the detection limit was 0.76 μM at a signal-to-noise ratio of 2. In addition, the sensor had good stability and reproducibility
  6. Keywords:
  7. Quinizarine ; TiO2 nanoparticles ; Tryptophan ; A-carbon ; Anodic waves ; Chemically modified ; D-Penicillamine ; Detection limits ; Electrocatalytic activity ; Good stability ; Linear range ; Modified carbon paste electrode ; Modified electrodes ; Optimal conditions ; Over potential ; Peak potentials ; Reproducibilities ; Simultaneous determinations ; Square wave voltammetry ; TiO ; Voltammetric determination ; Amino acids ; Electrochemical sensors ; Nanoparticles ; Sensors ; Signal to noise ratio ; Anodic oxidation
  8. Source: Journal of Electroanalytical Chemistry ; Volume 644, Issue 1 , Jan , 2010 , Pages 1-6 ; 15726657 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S1572665710000974