COVALENT IMMOBILIZATION OF IMMUNOGLOBULIN ON A WAFER SURFACE FOR IMMUNOSENSOR BIOSELECTIVE MATRIX CONSTRUCTION

Immunoglobulin G was immobilized on a wafer surface both covalently and adsorptively. For the preparation of a monolayer of covalently bonded groups, silylation with 3-aminopropyltriethoxysilane was carried out in anhydrous toluene with subsequent activation with glutaraldehyde solution. The properties of the immune slective matrix were compared with those of a bovine serum albumin matrix. According to the results of an immune-enzyme test, the bioselective matrix created from covalently bonded antigens shows a 10-15 times higher affinity than the loaded materials. Tris-HCl buffer can be used for the desorption of non-specific substances from the biowafer surface, and 50% ethylene glycol or 4 M carbamide solutions can be used for the regeneration of the antigen matrix after antisera treatment. Under these conditions, the affinity of the bioselective matrix did not decrease even after five cycles of immune chemical reaction during a period of at least 3 months.