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Published on: April 26, 2014
Toward high-performance refractive index sensor using single Au nanoplate-on-mirror nanocavity
Qifa Wang1, Liping Hou1, Chenyang Li1
1Key Laboratory of Light-Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710129, China. fjxiao@nwpu.edu.cn.
Researchers developed a novel plasmonic nanocavity sensor using gold nanostructures. This localized surface plasmon resonance (LSPR) sensor significantly enhances sensitivity and figure of merit (FOM) for refractive index sensing applications.
Area of Science:
- Nanotechnology
- Plasmonics
- Sensors
Background:
- Localized surface plasmon resonance (LSPR) sensors are valuable for chemosensing and biosensing.
- Traditional LSPR sensors face limitations in sensitivity and figure of merit (FOM) due to short decay length and radiation damping.
Purpose of the Study:
- To design and fabricate a plasmonic nanocavity sensor with enhanced sensitivity and FOM.
- To investigate the effect of a plasmonic gap mode on sensor performance.
Main Methods:
- Fabrication of a plasmonic nanocavity sensor with a hexagonal gold nanoplate over an ultrasmooth gold film.
- Utilizing strong coupling to form a plasmonic gap mode.
- Analyzing the interaction of the local field with glycerol solution.
Main Results:
- The plasmonic gap mode enhanced sensitivity by increasing local field interaction with the analyte.
- Reduced radiative damping was achieved through antiphase charge oscillation in the gap.
- Optimizing gap size yielded a record FOM of 11.2 RIU⁻¹ for single nanostructure LSPR sensing.
Conclusions:
- The plasmonic nanocavity sensor design overcomes limitations of conventional LSPR sensors.
- This approach offers a highly sensitive and efficient platform for refractive index sensing.
- The achieved FOM sets a new benchmark for LSPR sensing technology.
