Xie, LijuanGao, WeiluShu, JieYing, YibinKono, Junichiro2015-05-152015-05-152015Xie, Lijuan, Gao, Weilu, Shu, Jie, et al.. "Extraordinary sensitivity enhancement by metasurfaces in terahertz detection of antibiotics." <i>Scientific Reports,</i> 5, (2015) Nature Publishing Group: http://dx.doi.org/10.1038/srep08671.https://hdl.handle.net/1911/80220We 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.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articleimaging and sensingrisk factorshttp://dx.doi.org/10.1038/srep08671