Label-Free Photonic Crystal Biosensor Integrated Microfluidic Chip for Determination of Kinetic Reaction Rate Constants

We demonstrate a photonic crystal integrated microfluidic chip that is compatible with a 384-well microplate format for measuring kinetic reaction rate constants in high-throughput biomolecular interaction screening applications. The device enables low volume kinetic analysis of protein-protein interactions with low flow latency, and control of five analyte flow channels with a single control point. The structure is fabricated with a replica molding process that produces the submicron photonic crystal structure simultaneously with the micrometer-scale fluid channel structure. The device significantly reduces the kinetic assay time required compared with a conventional biosensor microplate in which reagents reach the active detection surface by diffusion. Using the photonic crystal sensor fluid network system, we demonstrate determination of the kinetic association/dissociation rate constants between immobilized ligands and analytes in the flow stream, using the heparin/lactoferrin system as an example.