Enhancement of Single-Molecule Fluorescence Signals by Colloidal Silver Nanoparticles in Studies of Protein Translation

Metal-enhanced fluorescence (MEF) increased total photon emission of Cy3 and Cy5-labeled ribosomal initiation complexes near 50 tun silver particles 4- and 5.5-fold, respectively. Fluorescence intensity fluctuations above shot noise, at 0.1-5 Hz, were greater on silver particles. Overall signal-to-noise ratio was similar or slightly Unproved near the particles. Proximity to silver particles did not compromise ribosome function as measured by codon-dependent binding of fluorescent tRNA, dynamics of fluorescence resonance energy transfer between adjacent tRNAs in the ribosome, and tRNA tianslocation induced by elongation factor G.