Fluorescent Core-Shell Ag@SiO_2 Nanocomposites for Metal-Enhanced Fluorescence and Single Nanoparticle Sensing Platforms

摘要

We report the development of highly versatile highly fluorescent core-shell Ag@SiO_2 nanocomposites, which allow researchers to incorporate any fluorophore to the outer-silica shell by two simple methods (i.e., simple doping or covalent attachment) while exploiting the benefits of using a silver core for MEF. To show the generality of the preparation technique, we have developed three different fluorescent probes: an organic fluorophore (Rh800) and a lanthanide probe doped (noncovalently linked), and another organic fluorophore (Alexa 647) covalently linked to the silica shell. When compared to the control sample fluorescent nanoparticles (nanobubbles), fluorescent nanoparticles with core-shell architecture yielded up to 20-fold (with Rh800) enhancement of the fluorescence signal and a potentially 200-fold increase in particle detectability.