Analytical methods for the investigation of adsorbed protein films at chemically modified surfaces

Surface analysis is becoming a dominant field of inquiry due to the drive towards miniaturization and ultimately, nanoscale manipulation and information encoding. At nanometric dimensions, surface-related phenomena play a central role in determining the properties of a system. As such, it is of fundamental importance to develop techniques for the measurement and control of the properties of surfaces and interfaces. The work presented in this thesis further developed the analysis and manipulation of surface chemistry for the interactions of proteins at the solid-liquid interface.; Tapping-mode scanning force microscopy (TM-SFM) was used to probe the physical properties of fibrinogen films adsorbed on a chemically patterned surface. The use of the phase lag signal generated by an oscillating cantilever was found to be able to discriminate regions of fibrinogen films adsorbed to a chemically patterned monolayer. The surface chemistry was seen to influence the degree of denaturation of the protein. The difference in the adsorbed film properties as a result of the bulk difference in conformational relaxation on different monolayer chemistries resulted in a different level of energy dissipation from the oscillating cantilever. This was attributed to the substrate-induced changes in dehydration of the protein at the solid-liquid interface.; The chemical patterning of surfaces for use in studies of protein adsorption, as well as for the controlled patterning of biomolecules on a surface plasmon resonance (SPR) imaging sensor element, constituted a major portion of this work. The techniques of microfluidic surface patterning and microcontact printing were used to generate patterned surface chemistries utilizing gold-thiolate interactions. Methods for the modification of PDMS via oxygen plasma were developed in order to aid in then microfluidic patterning of surface chemistry from organic solvents.; The technique of SPR imaging was utilized to conduct assays of protein-antibody interactions. The development of surface patterning methods was a key to utilizing the imaging mode of SPR. SPR imaging was also developed as a tool for the analysis of protein interactions with carbohydrate ligands. The microfluidic patterning techniques in conjunction with SPR imaging provided a useful means of obtaining inhibition data for synthetic multivalent glycosidic inhibitors of toxin activity.