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arXiv · 1410.3716

Ultrathin plasmonic nanogratings for rapid and highly-sensitive detection

Beibei Zeng·Yongkang Gao·Filbert J. Bartoli
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Abstract

We developed a nanoplasmonic sensor platform employing the extraordinary optical properties of one-dimensional nanogratings patterned on 30nm-thick ultrathin Ag films. Excitation of Fano resonances in the ultrathin Ag nanogratings results in transmission spectra with high amplitude, large contrast, and narrow bandwidth, making them well-suited for rapid and highly-sensitive sensing applications. The ultrathin nanoplasmonic sensor chip was integrated with a polydimethylsiloxane (PDMS) microfluidic channel, and the measured refractive index resolution was found to be 1.46x10-6 refractive index units (RIU) with a high temporal resolution of 1 sec. This compares favorably with commercial prism-based surface plasmon resonance sensors, but is achieved using a more convenient collinear transmission geometry and a significantly smaller sensor footprint of 50x50um2. In addition, an order-of-magnitude improvement in the temporal and spatial resolutions was achieved relative to state-of-the-art nanoplasmonic sensors, for comparable detection resolutions.

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Beibei Zeng, Yongkang Gao, Filbert J. Bartoli. 2014-10-14. Ultrathin plasmonic nanogratings for rapid and highly-sensitive detection. https://arxiv.org/abs/1410.3716

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