INVESTIGADORES
RUBIANES Maria Dolores
artículos
Título:
Electrochemical sensor for amino acids and glucose based on glassy carbon electrodes modified with multi-walled carbon nanotubes and copper microparticles dispersed in polyethylenimine
Autor/es:
FABIANA A. GUTIERREZ; MARÍA D. RUBIANES; GUSTAVO A. RIVAS
Revista:
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
Editorial:
ELSEVIER
Referencias:
Lugar: Amsterdam; Año: 2016 vol. 765 p. 16 - 21
ISSN:
0022-0728
Resumen:
This work reports the analytical performance of glassycarbon electrodes (GCE) modified with multi-walled carbon nanotubes (CNT) andcopper microparticles dispersed in polyethylenimine (PEI) (GCE/CNT-PEI-Cu) forthe quantification of amino acids, albumin and glucose. The best analyticalperformance was obtained with CNT-PEI-Cu prepared by sonicating for 15.0 min amixture of 1.0 mgmL-1 PEI, 1.0 mgmL-1 CNT and 3.0 mgmL-1copper. In the case of amino acids and albumin, the analytical signal wasobtained from the increase of copper oxidation signal produced as a consequenceof the complex formation between Cu(II) and the amino acids. The sensor allowedthe highly sensitive (submicromolar levels) and reproducible (3.9 %) amperometricquantification of hystidine, serine and cysteine at very low potentials (0.000V) and pH 7.40. Albumin was quantified by Square Wave Voltammetry after 10.0min interaction at -0.100 V with detection limits of 1.2 mg mL-1.GCE/CNT-PEI-Cu was also used for the quantification ofglucose by amperometry at 0.700 V in a 0.100 M sodium hydroxide solutionthrough the known catalytic activity of copper towards the oxidation of glucose,with highly competitive detection limits (182 nM). GCE/CNT-PEI-Cu wassuccessfully used for the quantification of amino acids and albumin in pharmaceuticalproducts and carbohydrates in beverages.