Anti-biofilm efficacy of low temperature processed AgCl–TiO₂ nanocomposite coating

Biofilms are a major concern in the medical settings and food industries due to their high tolerance to antibiotics, biocides and mechanical stress. Currently, the development of novel methods to control biofilm formation is being actively pursued. In the present study, sol–gel coatings of AgCl–TiO₂ nanoparticles are presented as potential anti-biofilm agents, wherein TiO₂ acts as a good supporting matrix to prevent aggregation of silver and facilitates its controlled release. Low-temperature processed AgCl–TiO₂ nanocomposite coatings inhibit biofilm formation by Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa. In vitro biofilm assay experiments demonstrated that AgCl–TiO₂ nanocomposite coated surfaces, inhibited the development of biofilms over a period of 10 days as confirmed by scanning electron microscopy. The silver release kinetics exhibited an initial high release, followed by a slow and sustained release. The anti-biofilm efficacy of the coatings could be attributed to the release of silver, which prevents the initial bacterial adhesion required for biofilm formation. - Highlights: • Potential of AgCl–TiO₂ nanocomposite coating to inhibit biofilm formation is exhibited. • Initial rapid release followed by later slow and sustained release of silver obtained. • TiO₂ being porous and inorganic in nature acts as a good supporting matrix