Open AccessPlasmonic interferometers for label-free multiplexed sensing
Author(s) -
Yongkang Gao,
Zheming Xin,
Qiaoqiang Gan,
Xuanhong Cheng,
F. J. Bartoli
Publication year - 2013
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.005859
Subject(s) - multiplexing , interferometry , optics , astronomical interferometer , plasmon , materials science , biosensor , refractive index , surface plasmon , surface plasmon polariton , optoelectronics , footprint , sensitivity (control systems) , physics , nanotechnology , computer science , electronic engineering , telecommunications , paleontology , engineering , biology
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 µm(2) 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.