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Updated: May 25, 2026
Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes
Published on: January 10, 2017
Development of a sensor for L-Dopa based on Co(DMG)(2)ClPy/multi-walled carbon nanotubes composite immobilized on
Fernando Roberto Figueirêdo Leite1, Camila Marchetti Maroneze, Adriano Bof de Oliveira
1Department of Chemistry, UFVJM, Rodovia MGT 367, Km 583, nº 5000, Alto do Jacuba, 391000-000, Diamantina, MG, Brazil.
Abstract:
L-Dopa is the immediate precursor of the neurotransmitter dopamine, being the most widely prescribed drug in the treatment of Parkinson's disease. A sensitive and selective method is presented for the voltammetric determination of L-Dopa in pharmaceutical formulations using a basal plane pyrolytic graphite (BPPG) electrode modified with chloro(pyridine)bis(dimethylglyoximato)cobalt(III) (Co(DMG)(2)ClPy) absorbed in a multi-walled carbon nanotube (MWCNT). Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy were used to characterize the materials. The electrocatalytical oxidation of L-Dopa using the Co(DMG)(2)ClPy/MWCNT/BPPG electrode was investigated by cyclic voltammetry and square wave voltammetry. The parameters that influence the electrode response (the amount of Co(DMG)(2)ClPy and of MWCNT, buffer solution, buffer concentration, buffer pH, frequency and potential pulse amplitude) were investigated. Voltammetric peak currents showed a linear response for L-Dopa concentration in the range of 3 to 100 μM, with a sensitivity of 4.43 μAcm(-2)/μM and a detection limit of 0.86 μM. The related standard deviation for 10 determinations of 50 μM L-Dopa was 1.6%. The results obtained for L-Dopa determination in pharmaceutical formulations (tablets) were in agreement with the compared official method. The sensor was successfully applied for L-Dopa selective determination in pharmaceutical formulations.
