Synthesis, structural and electrochemical characterization of nanomaterials aiming its application in electrochemical sensor development

In this work the effect of nanocomposite based on functionalized Carbon Nanotubes decorated with Silver Nanoparticles (CNTf-AgNP) and Gold Nanoparticles (CNTf-AuNP) as a modifier of Pyrolytic Graphite Electrode (PGE) surface was evaluated. By combining these two classes of nanomaterials, it is expected to obtain a synergistic effect that adds the high catalytic power of Metallic Nanoparticles (NPs) with the Carbon Nanotubes (CNT) excellent electrical conductivity, enabling an improvement in kinetics of redox processes, expanding the electrochemical signal and increasing the sensor sensitivity. The materials were synthesized and characterized by UV-Vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). Electrochemical characterization was performed by Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). The results confirmed the synthesis of CNTf-AgNP and CNTf-AuNP nanocomposites. Furthermore, CNTf-AgNP significantly enhanced the electroactive surface area of PGE, decreased the resistance to electron transfer and considerably increased the electron transfer rate, with current gain approximately 300% larger than the electrode without any modification. Therefore, the development of an electrochemical sensor obtained by a fast and simple solvent evaporation process was carried out effectively, with great potential and viability to be applied on different compounds of clinical, industrial and environmental interest determination. (author)