Plasmonic interferometers for label-free multiplexed sensing

Yongkang Gao, Zheming Xin, Qiaoqiang Gan, Xuanhong Cheng, Filbert J. Bartoli

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

We report a plasmonic interferometric biosensor based on a simple slit-groove metallic nanostructure that monitors the phase changes of surface plasmon polaritons resulting from biomolecular adsorptions. The proposed sensing scheme integrates the strengths of miniaturized plasmonic architectures with sensitive optical interferometry techniques. Sensing peak linewidths as narrow as 7 nm and refractive index resolutions of 1 × 10-5 RIU were experimentally measured from a miniaturized sensing area of 10 × 30 μm2 using a collinear transmission setup and a low-cost compact spectrometer. A high-density array of such interferometric sensors was also fabricated to demonstrate its potential for real-time multiplexed sensing using a CCD camera for intensity interrogation. A self-referencing method was introduced to increase the sensitivity and reduce sensor noise for multiplexing measurements. The enhanced sensing performance, small sensor footprint, and simple instrumentation and optical alignment suggest promise to integrate this platform into low-cost label-free biosensing devices with high multiplexing capabilities. © 2013 Optical Society of America.
Original languageEnglish (US)
Pages (from-to)5859-5871
Number of pages13
JournalOptics Express
Volume21
Issue number5
DOIs
StatePublished - Mar 11 2013
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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