Biological Sensing with Localized Surface Plasmon Resonances
Jason Hafner
Department of Physics, Rice University, Houston, TX
Date: March 7, 2008, Time: 3:30 pm, Location: W122-D3 Engineering Building 1, The University of Houston
Abstract:
Gold nanoparticles exhibit strong optical absorption and scattering which is tunable through the visible and near-infrared due to localized surface plasmon resonance (LSPR). This effect enables a range of biological and biomedical applications. For example, gold nanoparticles can transduce molecular binding at their surface through the dependence of their resonant wavelength on their local dielectric environment. We have developed self-assembled gold nanorod substrates which can track the binding and unbinding kinetics of antigen/antibody interactions based on this LSPR mechanism. Furthermore, we have studied the LSPR spectra of gold nanoparticles with complex shapes to find relationships between structure, resonant wavelength, and sensitivity. Gold “nanostars’ were found to be highly sensitive to refractive index and focus their sensing region to the molecular scale. Using single particle measurements of gold nanostars we are exploring the ultimate limit of LSPR sensing.