2009 Undergraduate Researchers
- Iuri Gagnidze
Steele Research Group
Work in my group centers around the plasmonic properties of metal wire
gratings. Wire gratings in my lab are generally made of gold wires
about 60 nm tall in arrays with periods ranging from 500 nm to 1700
nm. Under certain illuminating conditions, it is possible to excite
an optical resonance on the surface called a surface plasmon. Surface
plasmons consist of a wave of electrons from the metal that travels
along the surface of the wires, and are accompanied by intense
electromagnetic fields near the surface of the metal. Surface
plasmons have been used in a variety of sensing, lithography, and
light capturing applications. The broad range of surface plasmon
excitations possible on gratings make them ideal candidates for
applications involving a range of wavelengths, such as fluorescence
enhancement and photovoltaics.
I am currently looking for students to work on a project using wire
gratings to enhance fluorescence. Surface plasmons can enhance
fluorescence when there is sufficient overlap between the plasmon
resonant wavelength and either the absorption or emission wavelength
of the fluorophore. Surface plasmons can also provide an additional
decay channel for the molecules in the excited state, shortening the
lifetime of the molecules and therefore increasing the quantum yield
of the molecules. My group is continuing to maximize the enhancement
of fluorescence by changing grating parameters. I also plan to start
considering Förster resonance energy transfer (FRET) between
fluorophores. FRET utilizes a nonradiative energy transfer between
donor and acceptor fluorophores. FRET is heavily dependent on the
spacing of the molecules, making FRET a powerful tool for studying
spatial relationships in chemical and biological systems such as
protein configurations, protein-protein interactions, and DNA
hybridization. The broad ranges of surface plasmons that can be
excited on gratings make them an interesting system to manipulate and
enhance FRET between molecules.
Qualifications of successful applicants
Students wishing to work in my lab should have completed either PHYS 1310 or PHYS 1312 and Calc 2 or Calc B. Preference will be given to students who have also completed General Chemistry.
Work in my group is very interdisciplinary, pulling topics from
physics, chemistry, and optics. Students successful in my group come
with a strong basic understanding from their own major and a
willingness to fill in their knowledge gaps as they progress. I have
mentored students from engineering and chemistry as well as physics.
I especially like working with sophomores, but will consider any good
students.
