Monday, January 29th
Professor Richard P. VanDuyne
"Molecular Plasmonics for Surface Enhanced Sensing and Spectroscopy"

4:15pm - 5:15pm

Plasmonics is a materials driven subject. The unifying theme in this lecture will be the fabrication of size and shape-tunable, silver and gold nanoparticles using nanosphere lithography (NSL), electron beam lithography (EBL), and chemical synthetic methods. Size and shape tunability leads to an exquisite degree of control over the magnitude and spatial extent of the surface electromagnetic fields that surround optically excited nanoparticles. In turn, this has enabled fundamental new insights into the electromagnetic (EM) field enhancement mechanism underlying both LSPR and SER spectroscopy. This lecture will cover recent developments in three areas of plasmonics research: (1) surface enhanced Raman spectroscopy; (2) localized surface plasmon resonance spectroscopy; and (3) tip-enhanced Raman spectroscopy (TERS).

Within the area of surface-enhanced Raman spectroscopy, I will show SER spectra from nonresonant adsorbates on nanofabricated surfaces. This will be followed by a discussion of the relationship between the LSPR spectrum and wavelength-scanned SERS excitation spectra for silver nanoparticles. The use of these fundamental results to design a new generation of optimized and ultrastable SERS sensors will be briefly presented. A new approach to an existence proof for single molecule SERS will complete our treatment of this area. The principles and applications of localized surface plasmon resonance spectroscopy on both nanoparticle arrays and single nanoparticles will be presented. This will be followed by a new discovery concerning the LSPR spectroscopy of electronic resonances in adsorbate molecules that strongly couple to the localized plasmon resonance of the nanoparticle(s). Finally, I will present some new results from our tip-enhanced Raman spectroscopy (TERS) project. The focus will be force-dependent TERS and, hopefully, TERS in ultrahigh vacuum.