Saturday, May 16, 2015

Abstract-Extraordinary sensitivity enhancement by metasurfaces in terahertz detection of antibiotics

  • Lijuan Xie,
  • Weilu Gao,
  • Jie Shu,
  • Yibin Ying
  • Junichiro Kono
  • http://www.nature.com/srep/2015/150302/srep08671/full/srep08671.html?WT.ec_id=SREP-639-20150303

    We have detected trace amounts of molecules of antibiotics (kanamycin sulfate) dispersed on metasurfaces with terahertz (THz) spectroscopy. Utilizing the extraordinary optical transmission resonance of an array of square-shaped slits on a silicon substrate at ~0.3 THz, we were able to monitor varying concentrations of kanamycin sulfate as low as ~100 picogram/L. In contrast, the lowest detectable concentration of kanamycin sulfate on silicon without any metallic structure was ~1 gram/L. This dramatic ~1010 times enhancement of sensitivity is due to the near-field enhancement of THz electric fields by the metamaterial structure. This result thus demonstrates the power and usefulness of metamaterial-assisted THz spectroscopy in trace molecular detection for biological and chemical sensing as well as for food product quality and safety inspection and control.

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