Abstract

Plasmonic-Enhanced Single-Molecule Detection

Steve Blair, Professor, University of Utah

The next generation of molecular diagnostics tools are targeted to have single molecule sensitivity. Plasmonic-enhanced fluorescence can be a key enabling factor in achieving this goal. Large-scale arrays of plasmonic structures meet the requirements of enhanced signal-to-background in fluorescence detection, along with compatibility with existing instrumentation and surface chemistry. Fluorescence enhancement results from a combination of plasmonic mediated excitation and emission enhancement. Even though molecules are confined within a plasmonic structure, the spectral region of enhancement depends strongly on the metal. As such, have also been working with structures in Al, which is mass-production friendly and provides balanced enhancement throughout the visible spectrum, opening up a wider range of applications. However, new chemical passivation strategies need to be devised due to the native oxide of Al. Tuning of the relative enhancements can be accomplished by adjusting the shape of the plasmonic structures, opening up the UV spectral range where the native fluorescence of biomolecules can be accessed.