Plasmonic Amplification for Fluorescence Bioassays Utilizing Propagating Surface Plasmons

Plasmonics offers efficient means for enhancing sensitivity of fluorescence bioassays for detection of chemical and biological analytes. In this method, specific capture of target analyte from analyzed liquid sample at metallic sensor surface with attached recognition elements is observed by using fluorophore labels (e.g., organic dyes or quantum dots). These labels are probed by the confined field of surface plasmons that originate from collective oscillations of charge density at a surface of metallic films or metallic nanoparticles. The excitation of surface plasmons is accompanied with strongly increased intensity of electromagnetic field which couples with fluorophores. The combination of surface plasmon-enhanced excitation rate fluorophore absorption wavelength, improved quantum yield, and directional emission at the emission ...