Avidin-biotin micropatterning methods for biosensor applications

High-resolution patterning methods have been developed to immobilize functional proteins onto a silicon dioxide surface for biosensor applications. Antibody lines, as small as 5 mum in width, with intervening 5 mum spacings, were patterned on oxidized silicon wafers using avidin-biotin chemistry. The N-hydroxysuccinimide (NHS) ester of photoactivatable biotin was covalently bound to a self assembled monolayer (SAM) of 3-amino-propyltriethoxysilane (3-APTS) after irradiation by 350 nm ultraviolet (UV) light from a 25 W Hg are lamp. The patterned layers were evaluated using fluorescent imaging of Alexa-488 conjugated avidin and two fluorescence-conjugated antibodies. This technique allows binding of any biotinylated compound without exposure to harmful UV light, extreme pH, toxic chemicals, or high salinity.