Evanescent field sensors based on waveguide surfaces play an important rolewhere high sensitivity is required. Particularly tantalum pentoxide (Ta₂O₅) is a suitablematerial for thin-film waveguides due to its high refractive index and low attenuation.Many label-free biosensor systems such as grating couplers and interferometric sensors aswell as fluorescence-based systems benefit from this waveguide material leading toextremely high sensitivity. Some biosensor systems based on Ta₂O₅ waveguides alreadytook the step into commercialization. This report reviews the various detection systems interms of limit of detection, the applications, and the suitable surface chemistry.
Keywords: Ta2O5.; biosensors; evanescent field; label-free detection.