Abstract:
In this thesis the interaction of different sensitive layers with volatile organic compounds is investigated by surface plasmon resonance (SPR) with the aim of a selective and sensitive detection. Using the modified cyclodextrin octakis(3-O-butanoyl-2,6-di-O-n-pentyl)-cyclodextrin (Lipodex E) the enantioselective detection of the enantiomers of the inhalation anesthetic isofluran as well as of the chiral degradation product 1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropan (halodiether B) of the achiral inhalation anesthetic sevofluran can be performed. For the S-enantiomer of halodiether B an up to nine fold higher signal than for the R-enantiomer is measured using Lipodex E as sensitive layer.
Using a microporous polycarbonate as sensitive layer a high difference of the response times of methanol, ethanol and 1-propanol can be detected. If several measurement points during the exposition of the sensitive layer to the analyte are evaluated using neuronal networks a quantitative detection of these analytes in ternary mixtures is possible with one single sensor.
Homogeneously aligned nematic liquid crystals are highly birefringend. By rising the temperature or sorption of analyte the order of the nematic liquid crystal is disturbed. At the phase transition to the liquid phase the order and therewith the birefringence is completely lost. Therefore SPR-measurements with nematic liquid crystals show a high sensitivity towards various volatile organic compounds. Due to different partition coefficients of analytes in the nematic phase and the different disturbance of the order caused by them, nematic liquid crystals also show a selectivity towards different groups of analytes.