A new method for the pre-treatment of a commercially available carbon-nanofibre screen-printed electrode (CNF-SPE) using a single one-step process was evaluated and applied for the analytical determination of nitrofurans. The optimal pre-treatment conditions were found to include a soaking process in Britton-Robinson buffer/ Dimethylformamide (DMF) 70/30% solution for 15 min of activation time. Voltammetric curves were obtained for several biologically significant nitrofurans (furazolidone, nitrofurazone and nitrofurantoin) using the activated CNF-SPE, and a considerable increase in the peak current was observed. According to the chronoamperometric results, the calculated active area for a CNF-SPE activated with the pre-treatment was increased approximately 19 times compared to the active area of a non-activated electrode. Changes in the morphology of the electrode active area were observed in scanning electron microscopy (SEM) images after the activation pre-treatment. The carbon nanofibre surfaces became rougher and this increase in roughness was directly related to an enlargement of the electroactive area, with a corresponding increase in the active-site availability for the nitro compounds. The increase in the electrochemical activity of the activated surface was visualized with scanning electrochemical microscopy (SECM). In addition, a new approach to obtain SECM images on SPE is revealed. In order to apply the activated CNF-SPE, an analytical method using Linear-Sweep Voltammetry with a Flow Injection Analysis System (LSV-FIAS) was developed to analyze the nitrofurans in samples of chicken muscle, obtaining recoveries ranging from 97.2% to 102.7% and relative standard deviations between 1.9% and 5.2%.
Áreas temáticas de ASJC Scopus
- Materiales electrónicos, ópticos y magnéticos
- Energías renovables, sostenibilidad y medio ambiente
- Superficies, recubrimientos y láminas
- Química de los materiales