Deposition of silver dentritic nanostructures on silicon for enhanced fluorescence

Silver dendritic ("fractal") structures exhibit very high fluorescence enhancement, but their nonuniformity limits practical applications. Here, we present a novel, electroless deposition approach to produce uniform silver dendritic nanostructures on silicon for enhanced fluorescence. These metal-modified surfaces were allowed to bind a protein bovine serum albumin (BSA) labeled with the fluorescent dye Deep Purple. The effect of silver nanostructures on fluorescence intensity and lifetime in the presence of a conductive, absorbing substrate was analyzed, and high enhancement factors between 30 and 40 times were found. Such silicon-based structures with high fluorescence enhancement factors are suitable for integration with lab-on-chip and biosensing microelectronic Devices.