The best way to study dynamic fluctuations in single
molecules or nanoparticles is to look at only one
particle at a time, and to look for as long as
possible. Brownian motion makes this difficult, as
molecules move along random trajectories that carry
them out of any fixed field of view.
This thesis describes an instrument that tracks the
Brownian motion of single fluorescent molecules in
three dimensions and in real-time while measuring
fluorescence with nanosecond time resolution and
single-photon sensitivity. The apparatus increases
observation times by approximately three orders of
magnitude while improving data-collecting efficiency
by locking tracked objects to a high-intensity region
of the excitation laser.
Applications of the instrument to the study of
quantum dot photon statistics and of the thermal
intramolecular motion of flexible polymer chains are
Kevin McHale was born in Queens, New York in 1980. He was raised
in Queens and in Boca Raton, Florida. He received his B.A. in
Mathematics and B.S. in Chemistry from the University of Florida
in 2002, and completed his Ph.D. in Bioengineering at the
California Institute of Technology in 2008.