Spin coated thin-film polymer waveguide Mach-Zehnder interferometer for label-free streptavidin detection

We report the development of Mach-Zehnder interferometer biosensors based on spin coated thin-film high index contrast polymer waveguides. Despite the large wavelength of 1310 nm and the comparatively low index contrast in polymers, label-free online detection of streptavidin concentrations as low as 0.1 μg/ml (= 1.66 nMol) was achieved. The polymer-based optical sensor design is fully compatible with cost-efficient mass production technologies such as injection molding and spin coating.