RESUMO
Nowadays, modified electrodes with metal nanoparticles have appeared as an alternative for the electroanalysis of various compounds. In this study, gold nanoparticles (GNPs) were chosen as interesting metal nanoparticles for modifying carbon paste electrode (CPE). GNPs and the gold nanoparticles-modified carbon paste electrode (GNPs/CPE) were characterized by UV–Vis spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). GNPs/CPE as a simple and sensitive electrode was used to study three important biological molecules:folic acid (FA), uric acid (UA) and ascorbic acid (AA). Square wave voltammetry (SWV) was used as an accurate technique for quantitative measurements. A good linear relation was observed between anodic peak current (ipa) and FA (5.2 × 10?6–2.5 × 10?5 M), UA (1.2 × 10?6–2.1 × 10?5 M) and AA (1.2 × 10?6–2.5 × 10?5 M) concentrations in simultaneous determination of these molecules.