Enhanced fluorescence emission is detected from interacting protein pairs of dichlorotriazinylaminofluoresceinstreptavidin and biotinylated bovine serum albumin (see figure) that are adsorbed onto periodically spaced, square-patterned ZnO nanostructures. This florescence-enhancement capability of nanoscale ZnO and its potential easy integration into biosensor arrays may allow ultrasensitive protein detection, which is needed in the areas of biomedical research and in large-scale testing and screening.