Antibacterial Activity of a Novel Biocomposite Chitosan/Graphite Based on Zinc-Grafted Mesoporous Silica Nanoparticles

Introduction: A novel biocomposite chitosan/graphite based on zinc-grafted mesoporous silica nanoparticles (CGZM-bio) was synthesized and the antibacterial activities of this compound along with that of Zn-MSN nanoparticles were investigated. Methods: The CGZM-bio biocomposite was synthesized using sol-gel and post-synthesis method under UV radiation. The characterizations of the samples were carried out using FTIR, XRD, SEM, and nitrogen adsorption and desorption. The antibacterial activity was carried out against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) after 18 h at 310 K. Results: The suspension samples of the Zn-MSN and CGZM-bio (2-100 mu g.mL(-1)) presented antibacterial activities against S. aureus and E. coli. The minimum inhibitory concentration (MIC) values against E. coli for the Zn-MSN and CGZM-bio samples were 10 and 5 mu g.mL(-1), respectively, while the MIC against S. aureus for both nanomaterials was 10 mu g.mL(-1). Discussion: The antibacterial activities of these materials are due to the generation of radical oxygen species such as (OH)-O-center dot, H2O2, and O-2(2-) during the UV radiation via the generation of the electron-hole pairs which in turn damage the bacteria cells. These nanomaterials may be used in biomedical devices as antibacterial agents.