Energy transfer interactions between a terbium(III) complex and plasmonic metal nanoparticles

Metal nanoparticles (NPs) exhibit interesting opto-electronic properties such as a surface plasmon resonance, which results from collective oscillations of free electrons upon excitation by specific frequencies of incident light. Interactions between this plasmon resonance and other molecules can result in complex energy transfers within the NP system. Resonant energy transfers of lanthanide ion such as terbium(III), which glows yellow-green under short-wave radiation, have been studied extensively; however, there is a unique opportunity to explore plasmonic NP's influence in the resonant energy transfers which can quench or enhance the ion's luminescence. A one-pot synthesis of a novel terbium(III) compound coordinated 4-mercaptobenzoic acid, a bifunctional ligand, is reported, and a protocol to coordinate metal NPs to the available thiol group of the terbium(III) complex ligand is proposed. Optical spectroscopy was used to monitor the absorption and emission of the NP system and used to propose mechanisms of energy transfer of the system. NMR and FTIR spectra were used to characterize the physical properties of the system. Future applications for this system include adaption as luminescent probes.