Biotinylation of Silicon and Nickel Surfaces and Detection of Streptavidin as Biosensor

The availability of metal mesh device sensors has been investigated using surface-modified nickel mesh. Biotin was immobilized on the sensor surfaces consisting of silicon and nickel via a thiol–ene click reaction, known as the Michael addition reaction. Biotinylation on the maleimidated surface was confirmed by X-ray photoelectron spectroscopy. The binding of streptavidin to the biotinylated surfaces was evaluated using a quartz crystal microbalance and a metal mesh device sensor, with both techniques providing similar binding constant value. The recognition ability of the biotin immobilized using the thiol-maleimide method for streptavidin was comparable to that of biotin immobilized via several other methods. The adsorption of a biotin conjugate onto the streptavidin-immobilized surface via the biotin–streptavidin–biotin sandwich method was evaluated using a fluorescent microarray, with the results demonstrating that the biological activity of the streptavidin remained.