Fabrication of silica/polyrhodanine core/shell nanoparticles and their antibacterial properties

Silica/polyrhodanine core/shell nanoparticles were prepared by chemical oxidation polymerization. Polymerization proceeded preferentially on the surface of the silica nanoparticles where the initiator (Fe(III)ions) was located, resulting in core/shell nanoparticles. The size of the core/shell nanoparticles could be controlled by changing the diameter of the silica core. Polyrhodanine-coated silica nanoparticles exhibited excellent biocidal activities against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. It was confirmed that the bactericidal properties of the silica/polyrhodanine core/shell nanoparticles were due to the biocide contacting the bacteria. Additionally, bactericidal performance was enhanced with decreasing biocidal nanoparticle diameter due to increased surface area.