Ellipsometric Monitoring in Label-Free Microarray Biotechnologies
The surface of biochips prepared on the basis of silicon wafers for studies of reactions of pre-immobilized oligonucleotides and protein molecules was analyzed by high-resolution scanning ellipsometry. The hybridization interactions of nucleic acid (duplex formation in the reaction of an amplicon of the influenza A virus matrix protein gene with probe molecules), sorption of protein molecules, and protein-protein interactions on the surface of the biochip were detected. It was shown that pre-sorption of gold nanoparticles led to greater efficiency of immobilization of protein molecules on the biochip. The experimental data suggest that that ellipsometry is a highly sensitive, nondestructive and inexpensive label-free method for the detection of the biochip surface, which is suitable for quantitative analysis of reactions of biomolecules.