Plasmonics and Surface Enhanced Spectroscopy

Metallic nano-structures made from gold or silver display unusual optical properties not found in natural materials. This is due to the abundance of free electrons that are free to wiggle and propagate as plasmon waves. The rapidly emerging field of “plasmonics” is leading to significant new discoveries and numerous applications. In particular, plasmon waves give rise to extremely intense and localized optical fields. These can be exploited for surface-enhanced spectroscopy and biosensing.

Participants will be using a home-made laser scanning microscope. Based around a commercial Nikon microscope, a spectrometer, a HeNe laser, and sets of spectroscopy filters, participants will explore basic microscopy imaging techniques, laser-induced fluorescence, Raman spectroscopy, and chemical imaging of surfaces at micrometer scales. The participants will then explore the generation and exploitation of plasmons for surface-enhanced Raman spectroscopy (SERS). SERS is powerful optical biosensing and chemical identification technique, providing unique molecular “fingerprints,” and has received significant attention.

The immersion experiments would cover use of the microscope system, fabrication of low-cost plasmonic substrates, formation of molecular monolayers for SERS analysis, and spectroscopic chemical imaging of the SERS substrates. Time will also be spent exploring and customizing the microscope and laser setup. The microscope system has been used successfully by physics students (imaging, optical tweezers, metrology) as well as by chemistry and biology students (Raman identification of unknown samples, optical tweezing, fluorescence imaging).

Please see the Plasmonics and Surface-Enhanced Spectroscopy file (8.24MB pdf) for more information including experiment details.