Pollen-imprinted polyurethanes for QCM allergen sensors.
Molecularly imprinted polymers for detecting plant pollen were designed as artificial recognition materials for quartz crystal microbalances in the gaseous phase. Imprints of birch (diameter, 25 mum) and nettle (diameter, 15 mum) pollen can be generated by polydimethylsiloxane stamping technique as proven by atomic force microscopy. If pollen grains are able to access the cavities and thus are incorporated, the resulting sensors display Sauerbrey-like negative frequency shifts. Non-Sauerbrey behaviour can be observed as soon as pollen is prevented from entering the selective hollows: this results in grain mobility on the electrode surface leading to frequency increases. Access to the cavities is determined by the diameter ratio between pollen grains and imprints as can be revealed during cross-selectivity measurements of nettle and birch pollen imprinted layers. When the amount of pollen grains on the electrode surface exceeds the number of available imprints, the excess particles move freely, resulting in positive, non-Sauerbrey frequency shifts.
Jenik
Michael
M
Department of Analytical Chemistry and Food Chemistry, University of Vienna, Waehringer Strasse 38, 1090, Vienna, Austria.
Seifner
Alexandra
A
Lieberzeit
Peter
P
Dickert
Franz L
FL
D000485:Allergens / Q000032:analysis* / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D003460:Crystallization; D018625:Microscopy, Atomic Force; D054802:Molecular Imprinting / Q000295:instrumentation / Q000379:methods*; D011058:Pollen / Q000737:chemistry* / Q000276:immunology* / Q000648:ultrastructure; D011140:Polyurethanes / Q000737:chemistry*; D011791:Quartz
D000485:Allergens; D011140:Polyurethanes; D011791:Quartz