Synthesis of highly stable fluorescent Ag nanocluster @ polymer nanoparticles in aqueous solution.

Water-soluble, highly stable fluorescent Ag nanoclusters have been synthesized using a novel core/shell solid polymer (PMMA/PMMA-PMAA) nanoparticles as a novel template. The photoluminescence, ultraviolet-visible absorption, X-ray photoelectron (XPS), laser desorption time of flight mass spectroscopies (LDI-ToF-MS) and transmission electron microscopy (TEM) were carried out to characterize the optical properties and morphologies of Ag nanoclusters. The quantum yield of Ag nanoclusters reached 6% and the lifetime of Ag nanoclusters was 0.460 ns. Because of the protective structure of three-dimensional network of the polymer template, the Ag nanoclusters have high stability. And this highly stable fluorescent Ag nanoclusters have successfully been applied for bioimaging.