Síntesis y caracterización de óxido de grafeno funcionalizado con nanopartículas de cobre y plata obtenidos mediante procesos químicos y biológicos: evaluación de su actividad antimicrobiana

Abstract

The aim of this curricular integration work was to synthesise and characterise graphene oxide functionalised with copper and silver nanoparticles obtained by chemical and biological processes; also, to evaluate its antimicrobial activity in bacterial strains, Staphylococcus aureus, and Escherichia coli. For which the graphene oxide was synthesised by the modified Hummers method, the nanoparticles were obtained by top-down methods, in the synthesis of silver nanoparticles by chemical route sodium citrate was used, and by biological route calendula (Calendula Officinalis) was used. Ascorbic acid was used to produce copper nanoparticles by chemical route, while Persian lemon (Citrus limon) was used for the biological synthesis. Functionalisation of the graphene oxide with the metal nanoparticles allowed functional groups to be inserted to improve the antimicrobial properties, the functionalisation was carried out by magnetic stirring and sonication. The nanomaterials were characterised by Ultraviolet Visible Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive Xray Spectroscopy (EDS), Raman Spectroscopy, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) techniques. For the statistical analysis, the Anova test was used between the concentrations of the nanoparticles and the method of obtaining them, the results were significantly different, i.e. these factors directly influence the growth and inhibition of the bacteria. After the experimentation, it was possible to identify that the graphene oxide functionalised with silver nanoparticles presents greater inhibition in the strain (Staphylococcus aureus), inducing 99.9% of bacterial death in vitro. It is recommended to continue with the study of antimicrobial activity in different Gram-positive and Gram-negative strains to observe the influence of nanomaterials and find an alternative to bacterial resistance.