Preparation and characterization of core–shell structure of SiO 2@Cu antibacterial agent

Abstract

A simple, low cost and convenient method was used to prepare SiO 2@Cu core–shell composite using SiO 2 spheres as the core and copper nanoparticles as the shell. A uniform spherical particle of SiO 2 was fabricated according to an improved Stöber method. The SiO 2 spheres served as a support for the immobilization of copper by reducing Cu 2+ in aqueous solution using Fe power. The chemical structures and morphologies of the SiO 2 and SiO 2@Cu composite were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). E. coli ( Escherichia coli), S. aureus ( Staphylococcus aureus) and C. albicans ( Candida albicans) were utilized to test its antibacterial effect. Results of XRD, TEM and XPS demonstrated that the copper nanoparticles shell supported on the surface of SiO 2 spheres. With regard to the antibacterial effect, E. coli was more easily killed than S. aureus and C. albicans after 24 h incubation, and the pictures of TEM showed obviously morphological changes of the antibacterial activity. The results demonstrated that Cu supported on the surface of SiO 2 spheres without aggregation, which was proved to be a good novel antibacterial material.