Surface enhanced fluorescence on three dimensional silver nanostructure substrate

Multi-dimensional metallic nanostructures were fabricated by self-assembling silver nanoparticles on 3-aminopropyltrimethoxysilane-modified glass substrate and using p-aminothiophenol molecule as a linker. Surface enhanced fluorescence was investigated for Rhodamine 6G fluorophore molecules on the prepared 2D and 3D substrates. The experimental observation showed that the 3D nanostructured substrate presented stronger fluorescence enhancement, comparing with what was observed on the 2D nanoparticle arrays. Higher intensity of local electric field and stronger coupling of surface plasmon resonance in 3D silver nanostructure enhanced the excitation and emission of fluorophore molecules more effectively, leading to a stronger fluorescence enhancement on 3D nanostructured substrate. The result suggests that a metallic substrate with 3D nanostructures can produce better fluorescence enhancement, which is important for studying the mechanism and expanding the potential applications of enhanced fluorescence effect. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4709442]