Experimentalstudy of metasurface-based nanoantennas array fabricated using heavy ion tracking for biochemistry sensing

A novel metasurface-based nanoantennas array fabricated using a technique of heavy ion tracking is introduced. The technique has advantages of large area patterning, high aspect ratio of the nanoantennas, controllable length, and multi-choice of materials etc. Fabrication process, numerical calculation and optical near-field characterization of the structure are presented. Evidenced by probing results of our near-field scanning optical microscope, the sharp nanoantennas with high aspect ratio can scattering as tiny hot-spots with beam sops size as small as 50 nm in near-field region. Sensitivity of 137 nm/RIU is obtained for sensing ethanol on the basis of spectroscopy results. Our theoretical and experimental results demonstrate that this structure not only is capbale of acting as a biochemistry sensors for immunoassay and cell/molecular spectrocopy, but also has potential applications in bioimaging due to the nanofocusing hot-spots formed by the sharp nano-pillars array with high aspect ratio.