Fabrication of silver-loaded hollow mesoporous aluminosilica nanoparticles and their antibacterial activity

A facile and an effective route for the preparation of silver-loaded hollow mesoporous aluminosilica ([Ag]-HMAS) nanoparticles is reported. In our fabrication process, the solid silica nanoparticles are first converted into high-quality hollow mesoporous aluminosilica particles, and then silver ions are induced into the matrix through an ion-exchange method. By EDX and ICP analysis, it is found that the final [Ag]-HMAS particles have high silver loading (15.8 % by weight), and the release amount of silver ions can be effectively controlled by altering the concentrations of Na+ in the solution. The antibacterial properties of the [Ag]-HMAS particles against Escherichia coli (Gram-negative bacteria) and Bacillus subtilis (Gram-positive bacteria) are also investigated, both in liquid systems and on solid agar plates. The results show that the [Ag]-HMAS particles are highly effective against both Gram-negative and Gram-positive bacteria.