Hyunmin Yi1, Angela T. Lewandowski2, Xiaolong Luo1, Reza Ghodssi3, Gregory F. Payne4, Gary W. Rubloff3, and William E. Bentley5. (1) Department of Materials Science and Engineering, University of Maryland, Plant Sciences Bldg. Room 6142, College Park, MD 20742, (2) Department of Chemical and Biomolecular Engineering, University of Maryland, 5115 Plant Sciences Bldg., College Park, MD 20742, (3) Institute for Systems Research, University of Maryland, College Park, MD 20742, (4) Center for Biosystems Research, UMBI, Plant Sciences Bldg. Room 6138, College Park, MD 20742, (5) University of Maryland, College Park, 6143 Plant Science Bldg, College Park, MD 20742
There has been rapidly increasing attention on biosensing/biomedical applications exploiting the recent advances in micro/nanofabrication technologies. Despite such attention, assembling biomolecules at readily addressable locations while retaining the biological activities remains challenging. To attack this challenge of facile assembly we harness unique properties of the natural polysaccharide chitosan. The pH-responsive solubility transition of chitosan enables spatially selective, electric signal-guided assembly onto conductive surfaces, while its abundant primary amine groups can then serve as covalent coupling templates. Further, we take advantage of the enzyme tyrosinase as the in situ activator along with genetically fused tyrosine tags on the protein surfaces to achieve simple and robust protein assembly with high spatial, temporal and orientational control from the aqueous environment. In this presentation we report various facile protein assembly strategies we have developed, including in situ enzymatic activation of proteins for selective assembly onto electropatterned chitosan scaffolds both on-chip and within completely packaged microfluidic devices. We believe that our array of biomolecule assembly methods may provide generic approach for simple and programmable biofunctionalization in broad applications.