A Novel Fluorescence Spectral Deconvolution Method to Characterize Membrane
Mimetic Systems
Kerry K. Karukstis and Tyrel M. McQueen*
Surfactant molecules self-assemble into a variety of membrane-mimetic
microstuctures in aqueous solution. To characterize the structural
aggregates formed, we use a fluorescent probe that distributes into
multiple microregions of the aggregates present. Deconvolution of the
overall fluorescence emission spectrum into a sum of overlapping Gaussian
functions (the typical shape of spectral curves) enables an interpretation
of the probe location within discrete microdomains. We have developed an
alternative spectral deconvolution method that does not require an
assumption of the spectral band shape but fits the overall spectrum to a
sum of individual known spectra collected for various surfactant
aggregates. The fitting routine is based on fuzzy linear programming and
sets two constraints that any "good" solution must satisfy, namely that (1)
the sum of the areas of any solution must be very close to (or exceed) the
area of the target curve (thus placing a lower bound on the solution set),
and (2) at every point the sum of the solution values must not exceed the
target value by more than a set amount. In mathematically defining these
two constraints, a common fitting parameter is minimized to find the "best"
solution. We are currently optimizing this fitting algorithm for several
spectral probes used in investigations of surfactant systems.
Kerry K. Karukstis
Professor of Chemistry
Harvey Mudd College
301 East Twelfth Street
Claremont, CA 91711
E-mail: Kerry_Karukstis@hmc.edu
Phone: (909) 607-3225
Fax: (909) 607-7577