Streptavidin arrays as supramolecular architectures in surface-plasmon optical sensor formats

We describe a series of interfacial biomolecular architectures employed for studies aimed at elucidating the structural and dynamical factors governin g biorecognition and binding reactions between surface-attached biotin-deri vatives and analogues and streptavidin from solution. We compare binding ma trices based on mixed lipid monolayers transferred to a solid support from the water/air-interface and surface coatings based on binary mixed self-ass embled monolayers. The analytical techniques used to monitor the various la yers and the binding events are based on surface-plasmon spectroscopy and m icroscopy, in some cases in combination with electrochemical methods contro lling, in particular, the surface potential of electrode surfaces in contac t with aqueous electrolyte solutions. Finally, an example is given for the sensitivity enhancement obtainable by combining the field-enhancement of su rface-plasmon resonances with fluorescence detection schemes. (C) 2000 Else vier Science B.V. All rights reserved.