PATTERNING OF FUNCTIONAL ANTIBODIES AND OTHER PROTEINS BY PHOTOLITHOGRAPHY OF SILANE MONOLAYERS

We have demonstrated the assembly of two-dimensional patterns of funct ional antibodies on a surface. In particular, we have selectively adso rbed micrometer-scale regions of biotinylated immunoglobulin that exhi bit specific antigen binding after adsorption. The advantage of this t echnique is its potential adaptability to adsorbing arbitrary proteins in tightly packed monolayers while retaining functionality. The proce dure begins with the formation of a self-assembled monolayer of n-octa decyltrimethoxysilane (OTMS) on a silicon dioxide surface. This monola yer can then be selectively removed by UV photolithography. Under appr opriate solution conditions, the OTMS regions will adsorb a monolayer of bovine serum albumin (BSA), while the silicon dioxide regions where the OTMS has been removed by UV light will adsorb less than 2% of a m onolayer, thus creating high contrast patterned adsorption of BSA, The attachment of the molecule biotin to the BSA allows the pattern to be replicated in a layer of streptavidin, which bonds to the biotinylate d BSA and in turn will bond an additional layer of an arbitrary biotin ylated protein. In our test case, functionality of the biotinylated go at antibodies raised against mouse immunoglobulin was demonstrated by the specific binding of fluorescently labeled mouse IgG.