Metal-enhanced fluorescence of graphene oxide by palladium nanoparticles in the blue–green part of the spectrum

Graphene oxide (GO) has a wide fluorescence bandwidth, which makes it a prospective candidate for numerous applications. For many of these applications, the fluorescence yield of GO should be further increased. The sp²-hybridized carbons in GO confine the π -electrons. Radiative recombination of electron–hole pairs in such sp² clusters is the source of fluorescence in this material. Palladium nanoparticles are good catalysts for sp² bond formations. We report on the preparation of GO, palladium nanoparticles and their nanocomposites in two different solvents. It is shown that palladium nanoparticles can considerably enhance the intrinsic fluorescence of GO in the blue–green part of the visible light spectrum. Fluorescence enhancement has been attributed to the catalytic role of palladium nanoparticles in increasing the number of sp² bonds of GO with the molecules of the surrounding media. It is shown that palladium nanoparticles could be the nanoparticle of choice for fluorescence enhancement of GO because of their catalytic role in sp² bond formation. (paper)