Fluoreszenz basierte Methoden und neue Fluoreszenz-Farbstoffe zum Nachweis von Analyten in Lösung

In the thesis at hand a combination of capillary electrophoresis with the technique of single
molecule detection is studied. In that context separation of different analyte molecules could
be demonstrated on the single molecule level by using charged analyte molecules. Moreover
different analytes solved in a single sample were identified by their migration time as well as
by their fluorescence decay time. For this purpose fluorescent dyes were used as analyte
molecules. The optical set-up based on a confocal microscope with a laser diode as excitation
source. To determine the fluorescence decay time of the analyte molecules the technique of
time-correlated single-photon counting was used. The achieved sensitivity of the entire set-up
was high enough to detect and identify even individual molecules.
In the second part of this thesis new highly oil soluble fluorescent dyes and concentrates
were developed. The achieved solubility of the new fluorescent concentrates was as high, that
the fluorescence of a 2,000 times diluted sample could be seen with the naked eye. For
commercial purposes an optimized process could be designed so that the new compounds
could be synthesized in a single vessel.