Evanescent field Sensors Based on Tantalum Pentoxide Waveguides ￠ € “ A Review

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.