Colloidal-gold cysteamine-modified carbon paste electrodes as suitable electrode materials for the electrochemical determination of sulphur-containing compounds Application to the determination of methionine.

摘要: The suitability of colloidal-gold cysteamine-modified carbon paste electrodes (nAu-Cyst-CPE) for the electrochemical determination sulphur-containing compounds is illustrated in this work by determining amino acid methionine real samples, as well a methionine-based peptide. Voltammograms from solutions at nAu-Cyst-CPE exhibited improved electroanalytical characteristics when compared with Au disk (nAu-Cyst-AuE). Differential pulse voltammetry phosphate buffer pH 7.0 was used methionine, range linearity (1.0-100) x 10(-6)moll(-1) and detection limit 5.9 10(-7)moll(-1). This remarkably lower than those reported previously using other modified or amperometric detection. Methionine peptides also anodic peaks suitable to detect kind molecules. determined good results pharmaceutical product containing several vitamins, acids compounds, spiked meat peptone, complex sample enzimatically digested protein.