In the recent push toward single molecule spectroscopy and photochemistry, plasmonic nanostructures have emerged as an attractive and experimentally tractable design. The primary enhancement mechanism of the so-called “nantennas” arises from their ability to couple far-field radiation with molecular receivers, by confining the light in nm-scale junctions (“hotspots”). This small spatial confinement of radiation leads to enhancement factors large enough as to allow for single molecule detection.

The powerful combination of i) ultrafast lasers, ii) multiphoton photoemission, and iii)
high numerical aperture in-vacuo objectives provides a remarkably flexible and sensitive
experimental platform for exploring chemical physics of plasmonic materials on the
nanoscale. This talk will provide an overview of recent progress in the group. 1) The first
topic will be on exploiting novel high repetition rate (75 MHz) ultrafast OPO oscillators
to probe plasmonic properties of isolated nanostructures via scanning photoemission

Nanostructuring of thin metallic films can lead to either resonant or broadband absorption, followed by ohmic loss and energy dissipation as heat. However, if the absorption occurs near an interface, an opportunity arises to capture the energy prior to thermalization. In this talk, we will present our recent work on hot carrier generation and collection in metallic films and nanostructures and discussion future applications that could enable solar cells with efficiencies in excess of 40%.

That the conduction electrons inhabiting nanostructured metals and other conductors can sustain resonances involving the coherent, collective dynamics of the electrons – plasmon resonances – has been known and understood for the better part of a century. These resonances can store great quantities of energy, which on dephasing can result in numerous energetic electrons (and holes) which thermalize by electron-phonon interactions over a few picoseconds. Hot electron phenomena such as enhanced photoemission from plasmonic systems have been known for many years.

With recent FDA approval of biosimilars in the US emphasis on accurate and robust characterization is paramount. Regulations and guidelines (FDA and ICH) regarding what constitutes appropriate characterization include primary sequence analysis, secondary and tertiary structure analysis, and immnuohistochemical responses. This seminar highlights the current spectroscopic and biophysical methods that can be used to characterize biosimilars and biologics during the initial process development stage. These methods can also be applied to assay changes, if any, in the final drug product.