A support structure, such as an optical disc, is designed having surface structures formed on one or more surfaces of the support to enable formation of evanescent fields in a medium adjacent to the surface structures and allow for detection of optically-active substances within the evanescent fields in the medium. The surface structures may be formed in one or more areas on the surface of the support. The surface structures may have inclined surfaces that are inclined with respect to a general plane of the support surface, and form wedge structures or symmetric pyramidal structures, for example.