Uniform aligned bioconjugation of biomolecule motifs for integration within microfabricated microfluidic devices

Full details and a step-by-step guide suitable for printing proteins aligned to micron-sized sensors and subsequent integration and alignment of microfluidic structures are presented. The precise alignment and grafting of micron-sized biomolecule patterns with an underlying substrate at predefined locations is achieved using a novel semi-automated microcontact printer. Through integration of optical alignment methods in the x, y, and z directions, uniform contact of micron-sized stamps is achieved. Feature compression of the stamp is avoided by fine control of the stamp during contact. This printing method has been developed in combination with robust, compatible bioconjugate chemistry for patterning of a dextran-functionalized silicon oxide substrate with a NeutrAvidin-"inked" stamp and subsequent incubation with a biotin-functionalized protein. The bioconjugate chemistry is such that uniform coverage of the protein (without denaturation) over the printed motif is obtained and reproduction of the initial mask shape and dimensions is achieved. Later integration with a microfluidic structure aligned with the printed motif on the substrate is also described.