W. Knoll, F. Yu, T. Neumann, S. Schiller, R. NaumannSupramolecular functional interfacial architectures for biosensor applications.Physical Chemistry Chemical Physics. 5(23), 5169-5175 (2003)
This short review describes some of our efforts in generating bio-functional supramolecular interfacial architectures for their use as affinity coatings in biosensor development based on a recently introduced novel optical recording principle combining the resonant excitation of surface plasmon modes and fluorescence detection schemes. Examples are given for multilayer assemblies designed for surface hybridization reactions between a grafted oligonucleotide catcher probe and target strands from solution. By describing the binding behavior of fluorophore-labeled rabbit?anti-mouse IgG to surface-attached mouse IgG, the limit of detection of the surface plasmon fluorescence spectroscopy will be shown to be in the lower femtomolar concentration range. These DNA-and protein binding studies will be complemented by examples for membrane-based biosensor platforms. We will document that tethered lipid bilayer membranes can be assembled with specific capacities of Cm=0.5µF cm?2 and specific resistivities in excess of Rm>20 M? cm2. The incorporation of the synthetic ionophore valinomycin can mediate the K+-ion translocation across these tethered membranes, thus reducing the resistivity selectively and reversibly by more than four orders of magnitude.