silica nanoparticles can be physaborded easily by spin coating, drop casting or similar methods. To chemically bind the silica to the surface it may be useful to search for liteture doing to opsoite and design something based on the preciples other have developed.

Below is a paper that bound copper nanoparticles to silica, they prepared the silica surface and nanoparticles together then annealed the sample to 500 C. It may be that a similar approach works for silica nanoparticles where you form the particles in solution over the substrate and as the copper is reduced with annealing, the silica nanoparticles bind to the surface.

Good luck!

Article Cu and CuO Nanoparticles Immobilized by Silica Thin Films as...