A plastic colorimetric resonant optical biosensor for multiparallel detection of label-free biochemical interactions

A high sensitivity plastic biosensor based on detection of changes in optical density on the surface of a narrow bandwidth guided mode resonant filter is demonstrated. Using sub-micron microreplication of a master sensor surface structure on continuous sheets of plastic film, the sensor can be produced inexpensively over large surface areas. In this work, the sensor structure is incorporated into standard 96-well microtiter plates and used to perform a protein–protein affinity assay. A surface receptor immobilization protocol demonstrating low nonspecific binding is used to detect an antibody with 8.3 nM sensitivity. By measuring the kinetic interaction of a protein–protein binding pair simultaneously at several concentrations, the affinity binding constant can be quickly determined.