Optical fiber SPR Pb²⁺sensor with tip-printed Fabry-Perot interferometer for temperature compensation

Area of Science:

• Optoelectronics
• Environmental Science
• Analytical Chemistry

Background:

• Heavy metal ions, particularly lead (Pb2+), pose significant biological and environmental risks.
• Accurate and sensitive detection methods for heavy metal ions in liquid samples are crucial.

Purpose of the Study:

• To develop a novel fiber optic surface plasmon resonance (SPR) sensor for sensitive lead ion detection.
• To integrate temperature compensation for enhanced measurement accuracy.

Main Methods:

• Synthesized Schiff base and immobilized it on the SPR sensor surface for Pb2+ recognition.
• Utilized femtosecond laser-induced two-photon polymerization (TPP) to fabricate a fiber-tip miniature Fabry-Perot interferometer (FPI) for temperature sensing.
• Combined SPR and FPI channels for simultaneous Pb2+ detection and temperature compensation.

Main Results:

• Achieved a high sensitivity of -41.55 nm/μM for Pb2+ detection.
• Established a low detection limit of 7.05 nM for Pb2+.
• Demonstrated the FPI channel's linear temperature response, independent of Pb2+ concentration, enabling effective temperature correction.

Conclusions:

• The developed fiber optic SPR sensor offers high sensitivity, a low detection limit, and excellent stability, specificity, and repeatability for Pb2+ detection.
• The integrated FPI for temperature compensation enhances measurement reliability.
• The sensor presents a promising platform for biochemical testing and opens new avenues for compact, flexible optical sensor development.