Desenvolvimento de sensor eletroquímicos baseado em Carbono Black para a determinação de Trimetoprim

The use of carbon nanomaterials as nanodiamands, nanotubes and reduced graphene oxide has been extensively reported in literature for electrochemical sensors development due to enhanced electrocatalytic activity, high surface area and electronic properties [1,2]. However, the use of Carbon Black for this purpose is a quite new idea and, as well as for the other carbon based nanomaterials it presents outstanding electrochemical properties. In this work, glassy carbon (GC) electrodes had been modified with Carbon Black (25 µL of 1.0 mg mL-1 dispersion) for Trimethoprim (TMP) detection. The Carbon Black named as Printex 6L had been electrochemically and morphologically (FEG) characterised for pharmaceutical compounds determination. Parameters as electrolyte, pH and conditioning potential has been studied. The best experimental conditions determined were phosphate buffer, pH 4 and -0.2 V conditioning potential. The analytical methodology has been developed for square voltammetry (SWV) and differential pulse voltammetry (DPV) techniques. The material presented better electrochemical response for SWV. The analytical curve was linear in the range of 1.0x10-8 a 7.5x10-7 mol L-1 (R=0.99407) and detection limit of 3.4x10-9 mol L -1 .