Distance and Location-Dependent Surface Plasmon Resonance-Enhanced Photoluminescence in Tailored Nanostructures

This chapter introduces various mechanisms involved in the energy transfer between metal and fluorophores leading to enhancement or quenching of emission. Good control over absorption and emission of light is highly required for most of the fluorophore-based techniques. Upon illumination, absorption of photons followed by generation of excited ones occurred, and the energy of excited state is released mainly through emission of light, called as photoluminescence (PL). Resonance energy transfer (RET) and near-field enhancement (NFE) are two major mechanisms used to discuss the metal-enhanced fluorescence (MEF). The energy of the excited electrons is decayed mainly through two pathways, radiative decay and nonradiative decay. The process of Forster resonance energy transfer (FRET) involves the nonradiative energy transfer from an excited-state fluorophore to ground-state fluorophore via long-range dipole–dipole interactions. The chapter studies the enhancement of FRET in the presence of plasmonic metal and considers Surface Plasmon Resonance (SPR)-induced enhanced FRET..