Abstract:
This Master’s thesis investigates the applicability of non-traditional substrates for
surface-enhanced Raman spectroscopy and surface-enhanced fluorescence. The use of
silicon wafer for sandwich SERS immunoassay and aluminum foil for SEF in bacteria
labeling with quantum dots were assessed.
Perhaps the first application of silicon wafer for sandwich immunoassay resulted in
an analyte limit of detection of 30 pM with a dynamic range of 0.03-4 nM. In comparison
to gold film, it produced a signal intensity that was one order of magnitude lower, which
was compensated for by a significantly lower standard deviation in the blank signal.
The experiment on E.coli bacteria labeled with CdSeS/ZnS composite quantum dots
yielded a high level of surface enhancement for all three substrates including uncommon
aluminum foil and aluminum film. When the laser excitation source was changed, the
results remained consistent, and there was a clear distinction between labeled and unlabeled
cells.
Overall, both silicon wafer and aluminum foil showed comparable results to
conventional gold film and silver film substrates in different applications. Both of these
substrates were found to be less expensive and produced more reproducible results than
conventional substrates