Artificial circular dichroism [1] is investigated for developing novel devices for active polarization controllers, like rotators and modulators and high efficient molecular sensors. Here we show the chiral behavior raised by metal (Au) nanostructures on dielectric (polystyrene, PS) nanosphere substrate produced by a self assembled procedure that guarantees large area fabrication with low time consuming procedure (figure 1). In this material the artificial chirality [2,3] arises from the curvature of the gold layer covering the nanospheres and their reciprocal orientation [4].