Preparation of silver nanoparticles decorated mesoporous silica nanorods with photothermal antibacterial property

In this paper, we report the formation of rod-like silver nanoparticles in the internal porous channels of mesoporous silica nanoparticles (MSN) via in-situ reduction of silver ions (Ag+) by n-butylamine. This method was facile and mild. By carefully adjusting concentration of the silver source, the plasmonic absorption bands of the prepared MSN/Ag nanocomposites could be tuned and controlled in the visible to near-infrared region. TEM observation proved the formation of rod-like Ag nanoparticles in the channel pores and Ag nanospheres were also found on the external surfaces of the MSN. A green colored MSN/Ag-Gel hydrogel was further obtained by simply mixing the MSN/Ag nanocomposites with gelatin. It displayed efficient and repeatable photothermal conversion ability due to the excellent photothermal property of the incorporated MSN/Ag nanocomposites when irradiated by a 660 nm laser. And by virtue of this photothermal property, a bacterial killing efficiency of more than 99% could be achieved after incubating E. coli with the MSN/Ag-Gel hydrogel, in which concentration of MSN/Ag nanocomposites was at a relatively low value. These results make the MSN/Ag-Gel hydrogel an efficient and cost-effective material for antibacterial fields.