Fabrication of microchannels with patterned bio-active layers

Patterns of bio-active coatings on the inner surfaces of microchannels have been realized using a novel low-temperature, UV-epoxy glass-to-silicon bonding technique. Sucrose is applied as a protection layer for the immobilized bio-functional films during the bonding step. The bio-functional layer is composed of antibody patterns, for binding specific targets, next to polyethylene glycol (PEG) coated regions for preventing non-specific absorption. The activity of the patterned bio layer is tested, after the removal of the sucrose protection layer, utilizing fluorescent microscopy. A solution of fluorescent-labelled antigens is injected into the microchannels for incubation with the immobilized antibodies. Upon exposure to proper radiation, light is emitted only from the antibody patterns while the PEG regions remain dark. Hence, the sucrose-protection and UV-bonding techniques have not significantly compromised the functionality of the patterned antibodies, in binding to their counter receptors, and PEG molecules, in preventing non-specific adsorption, at the end of the fabrication process.