Fabrication and characterization of molybdenum(VI)complex-TiO2 nanoparticles modified electrode for the electrocatalytic determination of L-cysteine

Abstract

A novel voltammetric sensor for the determination of L-cysteine (L-Cys) was fabricated based on a TiO 2 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 (k s ) and charge transfer coefficient (α) of the TiO 2 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.

Electrochemical Characterization of Silver-Platinum Various Ratio Bimetallic Nanoparticles Modified Electrodes

“…2. The CVs of the modified GCEs at different scan rates (figure not shown) showed shifts in oxidation peak potential with increasing scan rates towards more positive potentials confirming the kinetic limitation of the electrochemical reaction [43] which is due to: (i) chemical interactions between the electrolyte ions and the modifier film, (ii) dominance of electrostatic factors, (iii) the lateral interactions of the redox couples present on the surface and/or (iv) non-equivalent sites present in the film [44]. Upon varying scan rates, linear relationship was observed between the peak current, I p and both the scan rate, v and its square root (Fig.…”

Voltammetric determination of carbidopa and folic acid using a modified carbon nanotubes paste electrode

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Preparation and Voltammetric Study of a Composite Titanium Phosphate/Nickel Hexacyanoferrate and Its Application in Dipyrone Determination

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