Plasmon-enhanced fluorescence of dye molecules

Enhanced fluorescence from Rhodamine 6G (R6G) mixed with gold colloids has been observed. We used fluorescence microscopy to correlate the fluorescence intensity of the dyes with the localized surface plasmon resonance (LSPR) spectra of the gold nanoparticles to which they are attached. Spectroscopic studies show that a 2.8-fold amplification of the fluorescence signal in presence of colloidal Au nanoparticles (GNP) was observed in resonance with plasmons. Such fluorophore-metal complex presents a unique opportunity for developing a new class of contrast agents for optical imaging and fluorescence based sensing, having a great potential for applications in the fields of medical diagnostics and biotechnology. (c) 2008 Elsevier B.V. All rights reserved.