A novel method for the preparation of Ru(bpy)32+-doped silica nanoparticles

A novel method for the preparation of spherical Ru(bpy)32+-doped silica nanoparticles with adjustable diameters and narrow particle size distribution with high yield was developed. Unlike the most commonly used Stöber method which uses a reverse microemulsion system (oil-based, NH4OH as a catalyst, pH 11–12), the proposed method synthesizes the nanoparticles in a water-based system (pH 9–10) using L-lysine as a catalyst in the presence of the dye. Both the size of the spherical dye-doped nanoparticles and the Ru(bpy)32+ content which is incorporated in silica nanoparticles are precisely controlled by the multiple-step addition of tetraethyl orthosilicate and Ru(bpy)32+ solution, respectively.

► A new method for doped silica nanoparticles was developed.
► The method does not use solvents or emulsions and produced large quantities.
► We demonstrated very tight control of particle size and distribution.