Highly sensitive evanescent wave SERS probe based on exposed-core optical fibers and its application

Area of Science:

• Optoelectronics
• Nanotechnology
• Chemical Sensing

Background:

• Evanescent wave fiber surface-enhanced Raman scattering (SERS) probes leverage the evanescent field of optical fibers for enhanced sensitivity.
• Exposed core optical fibers (ECFs) provide direct access to the evanescent field, enabling strong light-matter interactions and efficient analyte infiltration.
• Silver nanostructures are known to enhance Raman signals due to plasmonic effects.

Purpose of the Study:

• To develop a convenient, effective, and reproducible method for fabricating evanescent wave fiber SERS probes.
• To utilize ordered silver nanocolumn arrays on ECFs to enhance evanescent field intensity and light-matter overlap.
• To demonstrate the probe's capability for sensitive and in situ detection of specific analytes.

Main Methods:

• Fabrication of ordered silver nanocolumn arrays on the curved surface of an exposed core optical fiber (ECF).
• Utilizing the enhanced evanescent field and increased surface area for improved SERS detection.
• In situ detection of 4-aminothiophenol (4-ATP) and thiram using the developed ECF SERS probe.

Main Results:

• Achieved a low detection limit of 10^-10 M for 4-aminothiophenol (4-ATP).
• Demonstrated efficient in situ detection of both 4-ATP and thiram.
• The probe exhibited high sensitivity and reproducibility due to the synergy between ECF properties and silver nanocolumn arrays.

Conclusions:

• A cost-effective and reproducible method for fabricating highly effective evanescent wave fiber SERS probes was presented.
• The developed ECF SERS probe shows significant potential for label-free sensing and the detection of biomolecules.
• The combination of ECFs and silver nanocolumn arrays offers a promising platform for advanced chemical sensing applications.