Journal of the Serbian Chemical Society 2010 Volume 75, Issue 4, Pages: 537-549
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Polyaniline-multi-wall-carbon nanotube nanocomposites as a dopamine sensor
Sabzi Emamali Reza, Rezapour Kamran, Samadi Naser
A composite of polyaniline with multi-wall-carbon nanotubes (PANi/MWCNTs) was synthesized by an in situ chemical oxidative polymerization method. The PANi nanoparticles were synthesized chemically using aniline as the monomer and ammonium peroxydisulfate as the oxidant. The nanocomposites were prepared as a carbon paste using functionalized MWCNTs and PANi nanoparticles. The PANi/MWCNTs were characterized physically using scanning electron microscopy (SEM) and the electrochemical behavior of the composites in acidic solution (HCl) was investigated using cyclic voltammetry. The PANi/MWCNT composite electrode was used for studying dopamine (DA) as an electroactive material. The cyclic voltammetric results indicated that multi-wall carbon nanotubes (MWCNTs) significantly enhanced the electrocatalytic activity in favor of the oxidation of DA. The kinetics of the catalytic reaction was investigated using the chronoamperometry technique whereby the average value of the diffusion coefficient (D), the catalytic rate constant (K) for DA and the transfer coefficient (α) were determined to be 7.98 ± 0.8 × 10-7 cm2 s-1, 8.33 ± 0.072 × 104 dm3 mol-1 s-1 and 0.42, respectively.
Keywords: multi-wall-carbon nanotubes, dopamine, nanocomposite, polyaniline, sensor