Author(s): MOHAMMAD MAZLOUM-ARDAKANI | HADI BEITOLLAHI | ZAHRA TALEAT | MASOUD SALAVATI-NIASARI
Journal: Journal of the Serbian Chemical Society
ISSN 0352-5139
Volume: 76;
Issue: 4;
Start page: 575;
Date: 2011;
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Keywords: L-cysteine | TiO2 nanoparticles | carbon paste electrode | electrocatalysis
ABSTRACT
A novel voltammetric sensor for the determination of L-cysteine (L-Cys) was fabricated based on a TiO2 nanoparticles/bis[bis(salicylidene-1,4-phenylenediamine) molybdenum(VI)] carbon paste electrode. The electrochemical behavior of the sensor was investigated in detail by cyclic voltammetry. The apparent electron transfer rate constant (ks) and charge transfer coefficient (α) of the TiO2 nanoparticles/molybdenum(VI) complex/carbon paste electrode (CPE) were also determined by cyclic voltammetry and found to be about 4.53 s-1 and 0.54, respectively. The sensor displayed good electrocatalytic activity towards the oxidation of L-Cys. The peak potential for the oxidation of L-Cys was lowered by at least 130 mV compared with that obtained at an unmodified CPE. Under optimal conditions, the linear range spans L-Cys concentrations from 1.5×10-6 to 1.2×10-3 M and the detection limit was 0.70±0.01 µM at a signal-to-noise ratio of 2. In addition, the sensor showed good stability and reproducibility.
Journal: Journal of the Serbian Chemical Society
ISSN 0352-5139
Volume: 76;
Issue: 4;
Start page: 575;
Date: 2011;
VIEW PDF
DOWNLOAD PDF Original pageKeywords: L-cysteine | TiO2 nanoparticles | carbon paste electrode | electrocatalysis
ABSTRACT
A novel voltammetric sensor for the determination of L-cysteine (L-Cys) was fabricated based on a TiO2 nanoparticles/bis[bis(salicylidene-1,4-phenylenediamine) molybdenum(VI)] carbon paste electrode. The electrochemical behavior of the sensor was investigated in detail by cyclic voltammetry. The apparent electron transfer rate constant (ks) and charge transfer coefficient (α) of the TiO2 nanoparticles/molybdenum(VI) complex/carbon paste electrode (CPE) were also determined by cyclic voltammetry and found to be about 4.53 s-1 and 0.54, respectively. The sensor displayed good electrocatalytic activity towards the oxidation of L-Cys. The peak potential for the oxidation of L-Cys was lowered by at least 130 mV compared with that obtained at an unmodified CPE. Under optimal conditions, the linear range spans L-Cys concentrations from 1.5×10-6 to 1.2×10-3 M and the detection limit was 0.70±0.01 µM at a signal-to-noise ratio of 2. In addition, the sensor showed good stability and reproducibility.
