Borderline applications of QCM-devices: Synthetic antibodies for analytes in both nm- and μm-dimensions

Mass-sensitive devices are able to monitor both degradation processes of complex mixtures, such as automotive oils, and microorganisms by synthetic antibodies allowing detection of nm and μm particles. Pure ceramic materials (TiO₂) were synthesised by a sol-gel process, e.g. from titanium(IV) alkoxides (Ti(OR)₄) and imprinted by long chain carbonic acids. The sensor effect is based on the re-inclusion of oil oxidation products, e.g. carbonic acids. Surface imprinting with biological structures, such as microorganisms, yields pits for their adhesion and strongly enhanced mass-sensitivity of the sensor device. This effect depends very sensitively on both geometrical fitting and chemical interaction between the structured sensor layer and the analyte. Surprisingly, the specific interaction results in Sauerbrey and non-Sauerbrey sensor behaviours.