Silver half-shell arrays with controlled plasmonic response for fluorescence enhancement optimization

摘要

Regular arrays of interconnected silver half-shells (HSs) deposited on self-organized polystyrene microspheres are proposed as plasmonic substrates for metal-enhanced fluorescence. An emission enhancement of 28 times was demonstrated for Rose Bengal fluorophore placed at about 1 nm above HSs. The enhancement correlates with the spectral overlap between the fluorophore emission and the plasmonic resonance of the HSs, indicating a surface plasmon-coupled emission mechanism for the amplification. As the overlap can be easily tuned by controlling the diameter of underlying microspheres, such plasmonic structures could be relevant for building fluorescence-based sensing devices with optimized efficiency for any given fluorophore.