Desenvolvimento de eletrodos de carbono vítreo modificados com nanotubos de carbono funcionalizados imobilizados em filmes de hidrocloreto de poli(alilamina) para determinação de fármacos
Takeda, Humberto Hissashi
MetadataMostrar registro completo
Research involving carbon nanotubes (CNT) have a great attraction since its synthesis to the technology application. As part of the work was studied the formation and the stability of a functionalized Multiwall Carbon Nanotubes (MWCNTs) dispersion in a hydrochloride poly(allylamine) (PAH) polyelectrolyte solution 1.2 x 10-4 mol L-1 (MWCNTs/PAH) in order to use it for surface modification of a glassy carbon electrodes (GCE) by casting technique. Zeta potential measurements confirmed the stability of the MWCNTs/PAH dispersion. After this study were carried out modifications of GCE surfaces with the MWCNTs/PAH (GCE-MWCNTs/PAH) dispersion and found the electrochemical behavior of the film formed by cyclic voltammetry with potassium hexacyano ferrate (III) 6,6 x 10-4 mol L-1 in a potassium chloride solution 0, 1 mol L-1. The results proved the electrochemical effect provided by the MWCNTs and with the Randles-Sevcik equation we have obtained an active area for GCE-MWCNTs/PAH 1.2 times higher compared to the GCE bare. For further study, we evaluated the GCE-MWCNTs/PAH performance in a pharmaceuticals formulations with voltammetric and amperometric determinations, ciprofibrate, dopamine (DA), levodope (L-dopa) and carbidope. The ciprofibrate determination were measured by differential pulse voltammetry (DPV) and was used as supporting electrolyte a solution of sodium phosphate buffer 0.1 mol L-1 (pH 7,0). The analytical curve was linear in the ciprofibrate concentration range from 1.33 x 10-5 to 1.32 x 10-4 mol L-1 with a detection limit of 8.34 x 10-6 mol L-1. For DA determination was measured by amperometric measurement in a potential of 0.2 V in a phosphate buffer solution 0.1 mol L-1 (pH 7.0) as supporting electrolyte, and the analytical curve showed a linearity over the concentration range between 3.32 x 10-6 to 3.32 x 10-5 mol L-1 with a detection limit of 5.7 x 10-7 mol L-1. The L-dopa determination was done with the DPV and was used as a supporting electrolyte a sodium chloride solution (NaCl) 0.1 mol L-1. The analytical curve obtained showed a linearity over the concentration range of 2.00 x 10-6 to 2.72 x 10-5 mol L-1 and the limit of detection was 8.4 x 10-7 mol L-1. The carbidopa determination were measured by DPV and was used as a supporting electrolyte a NaCl solution 0.1 mol L-1 and the analytical curve xv showed a linearity over the concentration range of 2.00 x 10-6 to 2.34 x 10-5 mol L-1 and detection limit obtained was 6.50 x 10-7 mol L-1.