Achievement

An IGERT trainee has developed a sensing modality which exhibits the highest localized surface plasmon resonance (LSPR) shift due to changing dielectric environment. Clusters of plasmonic nanoparticles support Fano resonances. This spectral feature is produced by the interference between bright and dark modes of the nanoparticle cluster and is strongly dependent upon both geometry and local dielectric environment. This permits a highly sensitive tunability of the Fano dip in both wavelength and amplitude by varying cluster dimensions, geometry, and relative size of the individual nanocluster components. Plasmonic nanoclusters show an unprecedented sensitivity to dielectric environment with a local surface plasmon resonance figure of merit of 5.7, the highest yet reported for localized surface plasmon resonance sensing in a finite nanostructure.