Immunosensing platforms using spontaneously adsorbed antibody fragments ongold

This paper describes the construction and characterization of miniaturized antigenic immunosurfaces composed of spontaneously adsorbed Fab'-SH fragmen ts on gold. Rabbit Fab'-SH fragments contain a free sulfhydryl group that f orms a thiolate bond with a gold substrate as detailed by X-ray photoelectr on spectroscopy. This approach creates surfaces of higher epitope density, a factor critical to the early detection of disease, than surfaces composed of adsorbed whole molecule IgG on gold, The viability and specificity of a ntigenic Fab'-SH immunosurfaces is demonstrated using atomic force microsco py and confocal fluorescence microscopy, and possible explanations for the larger epitope density are discussed.