Directed-assembled multi-band moir\'{e} plasmonic metasurfaces

With the large number of component sets and high rotational symmetry, plasmonic metamaterials with moir\'{e} patterns can support multiple plasmonic modes for multi-functional applications. Herein, we introduce moir\'{e} plasmonic metasurfaces using both gold and graphene, by a recently developed directed-assembled method known as moir\'{e} nanosphere lithography (MNSL). The graphene moir\'{e} metasurfaces show multiple and tunable resonance modes in the mid-infrared wavelength regime. The number and wavelength of the resonance modes can be tuned by controlling the moir\'{e} patterns, which can be easily achieved by changing the relative in-plane rotation angle during MNSL. Furthermore, we have designed a metal-insulator-metal (MIM) patch structure with a thin Au moir\'{e} metasurface layer and an optically thick Au layer separated by a dielectric spacer layer. Benefiting from the combination of moir\'{e} patterns and field enhancement from the MIM configuration, the moir\'{e} metasurface patch exhibits strong broadband absorption in the NIR (\textasciitilde 1.3 $\mu $m) and MIR (\textasciitilde 5 $\mu $m) range. The dual-band optical responses make moir\'{e} metasurface patch a multi-functional platform for surface-enhanced infrared spectroscopy, optical capture and patterning of bacteria, and photothermal denaturation of proteins.