Reactive dye molecules are cross-linked to a silica precursor, which is reacted to form a dye-rich core particle. The heart of our work in functional core-shell silica nanoparticles is the development of fluorescent particles based on organic dyes covalently incorporated into the silica matrix. Bright and Stable Fluorescent Core-Shell Particles Iler, The Chemistry of Silica, Wiley Interscience, 1979Ģ. Wiesner,"Bright and Stable Core-Shell Fluorescent Silica Nanoparticles", Nano Letters 5 (1), 113-117 (2005) Wiesner, "Fluorescent core-shell silica nanoparticles: towards 'Lab on a particle' architectures for nanobiotechnology" Chemical Society Reviews 35, 1028-1042 (2006). Niktin, "Core-shell silica nanoparticles as fluorescent labels for nanomedicine" Journal of Biomedical Optics 12 (6) 064007-(1-11) (2007). This control also allows us to grow core-shell particles with different components in the core and shell layers to make multi-functional materials. Using the Stöber sol-gel process, we can grow particles from tens of nm to microns in diameter, simply by varying the catalyst and precursor concentrations. We have recently developed methods to use organosilicate chemistry to synthesize particles with functional architectures for applications in nanobiotechnology and nanophotonics.
The chemistry of silica has been extensively studied over the centuries, and has applications in glassware and optics, and more recently in creating nano-sized particles.