Copper and Its Alloy Nanostructures for Metal Enhanced /Quenched Luminescence

Enhanced signal and photostability of luminophores, improved surface immunoassay and DNA detection, and enhanced wavelength-ratiometric sensing, amplified assay detection are few examples of applications of metal enhanced luminescence.  On the other hand, quenching resulted due to metallic nanoparticles are successfully utilized for the improvement of homogeneous and competitive fluorescence immunoassay, optical detection of DNA hybridization, competitive hybridization assay and in optoelectronics.  In this work, metal enhanced/quenched luminescence was explored at the vicinity of copper and its alloy nanostructures. Silver copper alloy nanoparticles at different compositions (x=100, 67, 50, 40, 10 and 0) were studied.  Silver-copper nanoparticles of different composition were synthesized using the polyol process. It was observed that the luminescence of dye was strongly dependent on the Ag-Cu nanoparticles composition. Highest luminescence enhancement of dye Cy 3, commonly used for biological applications, was realized at the vicinity of pure silver nanoparticles. Enhancement effects were found to decrease as the percentage of copper increases in nanoparticles, leading to the quenching of fluorescence at the pure copper nanoparticles platforms. Signal manipulation of luminescent dye using different composition alloy nanoparticles is expected to extend it's application in different fields ranging from optoelectronics to biological research.