Influence of TiO2 nanostructure size and surface modification on surface wettability and bacterial adhesion

The aim of the study was to explore the synergistic effects of nanostructure size and surface treatment of TiO2 coatings on its wettability and bacteria adhesion. The coatings were fabricated by TiO2 particles with a diameter ranging from 25 nm to 300 nm. The surface wettability of coatings was tuned by chemical treatment. The anti-adhesion property of as-prepared coatings was evaluated with Streptococcus mutans in two types of solutions: phosphate buffer solution (PBS) and PBS with 1 wt% sucrose. The results show that particle size and surface treatment have significant influences on the wettability (with contact angles of 0-160 degrees) and bacterial adhesion. The coating prepared by chemically modified 25 nm particles has a superhydrophobic property, and could inhibit bacterial adhesion in aqueous solutions with sucrose or not. The study also provides a facile, universal and low-cost process to fabricate anti-adhesion coating, which is applicable for diverse of substrates.