Green Synthesis and Reversible Dispersion of a GiantFluorescent Clusterin Solid and Liquid Phase.

A water-soluble highly fluorescentsilver cluster on Au(I) surfacehas been synthesized with green chemistry under sunlight. The evolutionof the silver cluster is synergistic, demanding gold and glutathione.The fluorescent Au(I)core–Ag(0)shellparticlesare huge in size and at the same time they are robust. That is whythey become a deliverable fluorescing solid upon drying. Again, thegiant particles run into common water miscible solvents. As a result,the fluorescence intensity increases to a great extent without anyalteration of emission maxima. In this respect, acetone has been foundto be the best-suited solvent. To have a universal applicability ofthe fluorescent clusters, the particles in the water pool of a reversemicelle have been prepared to transfer the particles into differentwater immiscible solvents. The comparatively lower fluorescence intensityof the particles has been ascribed to a space confinement effect.Finally, giant-cluster-impregnated yellow-orange fluorescent polymerfilm and fluorescent cotton wool, as well as paper substrate, havebeen prepared. The antibacterial activity of the fluorescent particlehas also been tested involving modified cotton wool and paper substratefor Gram-negative and -positive Escherichia coliand Staphylococcus aureus, respectively. [ABSTRACT FROM AUTHOR]