Three-dimensional bio-photonic metamaterials (Invited Paper)

While numerous applications of plasmonic metamaterials to sensing and imaging the living matter are well-established, the effects of such photonic structures on the living matter itself are less explored. I will describe the concept of a designer bio-photonic metamaterial that can be used to (a) elicit specific responses from the living cells cultured atop of it, and (b) transduce such responses to optical signals. I will concentrate on several types of three-dimensional mixed-materials metasurfaces comprising plasmonic nano-antennas fabricated atop of tall high aspect ratio dielectric pillars. Cellular dynamics in aqueous environment is probed by illuminating the structures from below through an infrared-transparent substrate and collecting the reflected spectrum. By appropriately choosing the geometry of such elevated nano-antennas, we can induce the cells to wrap around them, thus enhancing the resulting reflected mid-infrared signal. We demonstrate that by increasing the height of the dielectric pillars, the penetration depth of the mid-infrared signal into the cell is also increased.