Characterization of anhydrous silanization and antibody immobilization on silicon dioxide surface

Formation of uniform and cluster free silane monolayer is one of the fundamental prerequisite for affinity cantilever based biosensors. We report anhydrous silanization protocol for uniform silane monolayer on silicon dioxide (SiO₂) surface using [3-(2-aminoethyl) aminopropyl)-trimethoxysilane (APTES) and characterized by AFM, spectroscopic ellipsometry and FTIR. Silanization coverage is controlled by availability of surface water. The roughness of the resulting silanized surface following our protocol is in the range of SiO₂ surface roughness. Silanized SiO₂ surface is used to immobilize human immunoglobulin (HIgG) on it. FITC tagged goat antihuman IgG is allowed to react with HIgG. The immobilized surface is further characterized using fluorescent spectroscopy and fluorescent microscope. Characterization results obtained from anhydrous silanization protocol are compared with the conventional aqueous silanization protocol