Tunable Ag@SiO₂ core-shell nanocomposites for broad spectrum antibacterial applications

Silica encapsulated silver nanoparticle core-shell nanocomposites of tunable dimensions were synthesised via a one-pot reverse microemulsion route to achieve controlled release of Ag⁺ ions for broad spectrum antibacterial application. Silver release rates and bactericidal efficacy against Gram-positive and Gram-negative bacteria, S. aureus and P. aeruginosa respectively, were inversely proportional to nanoparticle core diameter (3-8 nm) and silica shell (7-14 nm) thickness, and readily tuned through a facile hydrothermal etching protocol employing a PVP stabiliser to introduce mesoporosity.