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Published on: August 30, 2012
Organic plasmon-emitting diodes for detecting refractive index variation
Nan-Fu Chiu1, Chih-Jen Cheng, Teng-Yi Huang
1Institute of Electro-Optical Science and Technology, National Taiwan Normal University, No. 88, Sec. 4, Ting-Chou Road, Taipei 11677, Taiwan. nfchiu@ntnu.edu.tw
Sensors (Basel, Switzerland)
|July 2, 2013
Summary
Researchers developed a novel organic plasmon-emitting diode for sensitive refractive index sensing. This device enables naked-eye detection of glucose concentration changes, offering a low-cost, disposable sensor solution.
Area of Science:
- Optoelectronics
- Plasmonics
- Chemical Sensing
Background:
- Surface plasmon grating coupled emissions (SPGCEs) are generated using a photo-excited organic layer on a metal thin film with a corrugated substrate.
- Directional emissions align with resonant conditions of surface plasmon modes at the Au/air interface.
Purpose of the Study:
- To investigate the potential of organic plasmon-emitting diodes for refractive index sensing.
- To evaluate the device's sensitivity, linearity, and visual detection capabilities.
Main Methods:
- Fabrication of an organic layer on a corrugated metal thin film substrate.
- Excitation of surface plasmon modes to generate SPGCEs.
- Correlation of spectral shifts with changes in refractive index (glucose concentration).
Main Results:
- SPGCEs exhibited high directionality with intensity increases up to 10.38-fold.
- A spectral shift from 545.3 nm to 615.4 nm was observed with increasing glucose concentration (10-40 wt%).
- The sensor demonstrated a resolution of 1.056 × 10-3 RIU and a naked-eye detection limit of 0.6 wt% glucose.
Conclusions:
- Organic plasmon-emitting diodes are effective for refractive index sensing.
- The developed sensor offers a wide linearity range and high sensitivity, enabling naked-eye detection.
- This technology holds promise for low-cost, integrated, and disposable refractive index sensors.
