Molecular patterning on carbon based surfaces through photobiotin activation

We have demonstrated the site-specific adhesion of photobiotin as a method of producing protein micropatterns. These patterns were created by the sele ctive UV irradiation of a thin film of deposited photobiotin. The UV activa ted areas of photobiotin were then developed using fluorescently labelled a vidin. The size of pattern produced is an order of magnitude smaller than t hose previously reported by this method. The patterns were characterised us ing atomic force microscopy (AFM) to determine their microstructure. It was found that the AFM could discriminate between the areas of protein immobil ised to the surface through the activated photobiotin, and the bare substra te surface where the inactivated photobiotin had been removed during the wa shing process. The potential of these patterns as sensing surfaces is demon strated through the creation of a spatially patterned immunosensing surface . In this case, a biotinylated antibody was bound to the surface and the pa ttern developed using a second antibody specific to the immobilised biotiny lated antibody. This technique could thus provide a simple and efficient me thod of producing high density immunoassay systems.