Desempenho e caracterização de um novo sensor eletroquímico baseado em Fe3O4/MWCNT-O na detecção do herbicida Metribuzin

Abstract

Over the past years, new nanomaterials have been used as modifiel compounds to improve the selectivit and sensitivit of electrodes, among these materials carbon nanotubes and metalic oxides have been getting attention due unique characteristics. Here we propose a new electrochemical sensor based on Fe3O4/MWCNT-O nanocomposite toward Metribuzin determination. The magnetic nanoparticles were synthesized by co-precipitation method and multi-wall carbon nanotubes (MWCNT-O) were decorated with iron oxide (Fe3O4). This materials were severely characterized by FTIR and XRD. The surface area and volume size were realized by BET method. The thermal stability was analyzed by TGA/DSC and morphology were studied via TEM and SEM. By means of redox probe the electrodes were electrochemical characterized and kinetics parameters were calculated as activated surface area and charger transfer rate. When applied to electroanalytical, under optimized condition, time pulse 0.07 s, amplitude pulse 0.9 V, interval time 0.7 s, our sensor show linear range between 0.5 and 4.2 μmolL-1, with quantification limit 0.46 μmolL-1 and detection limit 0.15 μmolL-1. This result suggest our electrode can be used to quantify Metribuzin.