Real-time analysis of protein adsorption to a variety of thin films

The ability of a fluorescence-based array biosensor to screen surfaces for the adsorption of biomolecules in real-time is demonstrated. Glass microscope slides were coated with silanes, including 3-mercaptopropyl-triethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxy-silane, octadecyl-trichlorosilane, and 2-methoxy((polyethylenoxy)propyl)tri-methoxysilane, or with polymer thin films, including polystyrene, polyimide, sol-gel, poly(dimethylsiloxane), and agarose. The adsorption of Cy5-labeled proteins, bovine serum albumin, fibrinogen, and lysozyme onto these surfaces was measured using total internal reflection spectroscopy over a period of 50 min. The majority of the modified surfaces, apart from notable exceptions including the thiol silane and PDMS, behaved as expected upon protein adsorption, and the observations could be related to the properties of both the individual surfaces and proteins. This study highlights the complex nature of the mechanisms involved when a protein interacts at a solid-liquid interface. However, it also demonstrates a comparatively generic method with which to screen surfaces for their protein resistant properties and to measure surface interactions in real time. Furthermore, since the array biosensor can perform multiple measurements simultaneously, the interactions of a variety of proteins with a single surface can be monitored.