Metal enhanced fluorescence of different metallic nanoclusters deposited on silver dendritic nanostructures

Abstract

Abstract Plasmonic nanoclusters (NCs) have been introduced as new fluorescent materials that have low toxicity and do not undergo photo‐bleaching. Several factors including size and type of the NCs, surface chemistry and even solvent affect their luminescence. Despite extensive studies on tuning the fluorescence properties of NCs by manipulation of the above‐mentioned factors, very few researches have been focused on metal enhanced fluorescence (MEF) of them. In this study, the fabrication of silver dendritic nanostructured surfaces (DNSs) with numerous hotspots and unique plasmonic properties were optimized and DNSs were used as the substrates for fluorescence enhancement of NCs. NCs made of gold, silver and copper were synthesized by different stabilizing agents and compared with each other in terms of their MEF characteristics. The results showed that the stabilizing agent, the synthesis method and type of NCs affected their fluorescence enhancement by the DNSs. Copper NCs stabilized by bovine serum albumin (BSA) had the highest rate of fluorescence enhancement, with enhancement factor of 4.8 ± 0.8. Gold NCs synthesized by glutathione (GSH) and bovine serum albumin (BSA) demonstrated 3.9 ± 0.6 and 3.1 ± 0.4 fold fluorescence enhancement, respectively. The possibility of fluorescence enhancement of NCs in the vicinity of plasmonic nano‐structures introduces attractive platforms for sensing purposes.