Controlled release and absorption resonance of fluorescent silica-coated platinum nanoparticles

Aggregation-driven seeded growth of uniform platinum nanoparticles and exclusive silica-coating of the as-grown platinum nanoparticles have been achieved successfully. Fluorescent Pt@SiO2 nanoparticles have also been reproducibly prepared via effective co-condensation of silanized dye molecules with tetraethylorthosilicate. The dye-loaded Pt@SiO2 nanoparticles have been exploited as model carriers for thermal-responsive controlled release of guest molecules via slow hydrolysis/dissolution of silica shells; importantly, the encapsulated platinum cores have also been used as nanoprobes to simultaneously investigate their controlled release process. Meanwhile, unique size-sensitive absorbance resonance in the dye-loaded Pt@SiO2 nanoparticles has been demonstrated for the first time, and it is expected to find novel application.