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A Silicon-tipped Fiber-optic Sensing Platform with High Resolution and Fast Response
Published on: January 7, 2019
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Citrate polymer optical fiber for measuring refractive index based on LSPR sensor.
Fatemeh Arefnia1, Mohammad Ismail Zibaii2, Azam Layeghi1
1Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 19839 69411, Iran.
Scientific Reports
|August 11, 2024
Summary
This study introduces a novel polymer optical fiber localized surface plasmon resonance (LSPR) sensor for biomedical refractive index (RI) detection. The biocompatible, degradable sensor demonstrates high sensitivity, promising for point-of-care diagnostics.
Area of Science:
- Biomedical Engineering
- Materials Science
- Optical Sensing
Background:
- Fiber optic localized surface plasmon resonance (LSPR) sensors offer high sensitivity for refractive index (RI) detection in biomedical applications.
- Conventional optical fibers face limitations for in-body implantation, necessitating alternative materials and designs.
- Polymer optical fibers (POFs) present a flexible, biocompatible, and potentially degradable alternative for implantable sensors.
Purpose of the Study:
- To design and construct a novel polymer-based LSPR sensor for enhanced biomedical RI detection.
- To address the limitations of conventional optical fibers for in-vivo sensing applications.
- To develop a highly sensitive, label-free biosensor for point-of-care diagnostics.
Main Methods:
- Utilized finite element method (FEM) for theoretical design and testing of the polymer optical fiber (POF) sensor.
- Fabricated a step RI structure using poly(octamethylene maleate citrate) (POMC) core and poly(octamethylene citrate) (POC) cladding.
- Enhanced light coupling efficiency to the POF using a microsphere fiber optic tip and immobilized gold nanoparticles (AuNPs) via plasma surface treatment for LSPR sensing.
Main Results:
- The developed POF is biocompatible, flexible, and degradable, with degradation rates of 22% and 27% over 12 days.
- Achieved a light coupling efficiency of 77.8% to the POF with the microsphere tip.
- Demonstrated a high RI sensitivity of 7778%/RIU, approximately 5 times greater than previous RI POF sensors, with AuNP immobilization following pseudo-first-order kinetics.
Conclusions:
- The novel polymer optical fiber LSPR sensor offers a promising solution for sensitive, label-free refractive index detection in biomedical settings.
- The sensor's biocompatibility, flexibility, and degradability make it suitable for point-of-care applications, including neurosciences.
- The results align with theoretical predictions and simulations, validating the sensor's design and performance.
