Evaluation of antimicrobial activity and adsorption of silica nanoparticles doped with CuO

ABSTRACT Nanomaterials exhibit properties that apply in a wide range of area, including health and agriculture, where research is progressively increasing. In this work we synthesize non-porous silica nanoparticles doped with copper oxide (CuO) using Stöber's method with small modifications. In addition, the antimicrobial activity of these compounds against Staphylococcus aureus. Escherichia coli and Candida albicans was evaluated. First, the nanomaterial was characterized by X-ray diffraction to identify the CuO phase in the silica matrix, and Fourier transform infrared spectroscopy identifying the main SiO2 vibration bands and the CuO functionalization. Finally, the particle morphology was observed by scanning electron microscopy which showed formation of spherical nanoparticles size ~70 nm. CuO-doped silica nanoparticles showed efficiency in the inhibition of the three types of microorganisms tested in this work, forming inhibition halos between 19.0 and 25.0 mm. In the adsorption tests using methylene blue, it was possible to observe that the presence of CuO on the surface of the silica nanoparticles modified the adsorption characteristics, increasing the adsorption capacity and kinetics and thus showing to be a nanomaterial with interesting characteristics for applications in the agriculture and in different areas of health.