Plasmonic Approach to Enhanced Fluorescence for Applications in Biotechnology and the Life Sciences

摘要

One of the most rapidly growing areas of physics andnnanotechnology is concerned with plasmonic effects on thennanometer scale; these have applications in sensing and imagingntechnologies. Nanoplasmonic colloids such as Ag and Au have beennattracting active interest, and there has been a recent explosion in thenuse of these metallic nanostructures to modify the spectral propertiesnof fluorophores favorably and to enhance the fluorescence emissionnintensity. In this feature article, we summarize our work over a rangenof nanoplasmonics-assisted biological applications such as flowncytometry, immunoassays, cell imaging and bioassays where we usencustom-designed plasmonic nanostructures (Ag and Au) to enhancenfluorescence signatures. This fluorophore−metal effect offers uniquenadvantages in providing improved photostability and enhancednfluorescence signals. We discuss the plasmonic enhancement of lanthanide fluorophores whose long and microsecond lifetimesnoffer the advantage of background-free fluorescence detection, but low photon cycling rates lead to poor brightness. We alsonshow that plasmonic colloids are capable of enhancing the emission of fluorescent nanoparticles, including upconvertingnnanocrystals and lanthanide nanocomposites.