Patterning antibodies for a multiple analyte sensor via photodeprotection chemistry

In order to maximize the applications of advanced optical techniques for immunoassay it is critical that one can analyze multiple analytes simultaneously. One method of creating a multiple analyte sensor is to pattern antibodies against ligands of interest onto distinct regions of a single waveguide for fluorescence immunoassay. To achieve protein patterning, we are using a photolabile protected biotin with the caging moiety MeNPOC, (methyl nitropiprionyloxy carbonyl). The biotin molecules within a given region are selectively deprotected by exposure to ultraviolet light and subsequently bound to streptavidin. Incubation with a biotinylated antibody results in a functionalized region on the surface. This paper characterizes the method for immobilizing caged biotin onto the wave guide surface. Two surface biotinylation methods were examined silane coupling via aminpropyl triethoxy silane to a biotin-MeNPOC ester, and adsorption of biotin-MeNPOC conjugated bovine serum albumin. Using an I-125 label, protein surface densities have been determined for streptavidin bound to protected and deprotected surfaces. In addition, the duration of ultra-violet light exposure was evaluated to assess the ultimate effect on bound protein. The ability of an antibody bound within a patterned region to detect its corresponding analyte was determined.

Duke Scholars

Author William M. Reichert Biomedical Engineering