Ionic Liquid-Assisted Synthesis of Multicolor Luminescent Silica Nanodots and Their Use as Anticounterfeiting Ink

Here we propose a simple route for the fabrication of silica nanodots which are strongly photoluminescent in both solution and the solid state based on the use of ionic liquids (ILs). It is found that the ILs not only provides the environment for the reaction but also contributes to the quantum yield (QY) of the silica nanodots. In particular, the produced silica nanodots also displayed excitation-dependent photoluminescence and temperature sensitive properties. Based on the unique optical properties, the as-prepared nanomaterial was used for anticounterfeiting application and the results demonstrated the great potential of the silica nanodots alone or combined with other fluorescent material of unicolor for an improved anticounterfeiting technology. This simple approach and the resulting outstanding combination of properties make the prepared silica nanodots highly promising for myriad applications in areas such as fluorescent anticounterfeiting, optoelectronic devices, medical diagnosis and biological imaging.