Nucleic acid functionalized fiber optic probes for sensing in evanescent wave: optimization and application

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Evanescent wave fiber optic (EWFO) biosensors offer advantages in device configuration and sensing.
• Effective surface modification is crucial for EWFO biosensor performance, requiring minimal nonspecific adsorption and high-quality DNA immobilization.

Purpose of the Study:

• To optimize the surface modification of EWFO biosensors for improved DNA immobilization and reduced nonspecific adsorption.
• To develop reliable DNA-functionalized EWFO probes using a novel etching technique.
• To demonstrate the efficacy of the developed EWFO sensor for detecting adenosine.

Main Methods:

• Surface modification of EWFO probes using a novel HF/HNO3 mixture etching solution.
• Characterization of surface morphology and composition using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).
• Optimization of DNA immobilization strategies and evaluation of EWFO sensor performance for adenosine detection.

Main Results:

• The novel HF/HNO3 etching solution significantly improved the surface planeness of EWFO probes.
• Optimized immobilization techniques and surface properties led to enhanced EWFO biosensor performance.
• A split aptamer-based sandwich EWFO sensor successfully detected adenosine with a limit of detection (LOD) of 25 μM.

Conclusions:

• The study presents an optimized fabrication method for DNA-functionalized EWFO probes, enhancing their sensing capabilities.
• The findings provide insights into silica-etching mechanisms and inspire further research in EWFO biosensor development.
• The developed EWFO sensor demonstrates potential for sensitive and specific molecular detection.