Sensitivity studies for specific binding reactions using the biotin/streptavidin system by evanescent optical methods

Area of Science:

• Biophotonics
• Biosensing
• Surface Chemistry

Background:

• Evanescent optical methods are crucial for characterizing molecular interactions.
• Developing reusable affinity sensors requires understanding binding matrix architecture.
• Biotinylated self-assembled monolayers serve as a key platform for biosensor development.

Purpose of the Study:

• To design a highly specific, sensitive, and reusable affinity sensor for antigen detection.
• To characterize biotinylated self-assembled monolayers and streptavidin binding.
• To investigate the potential of an integrated optical Mach-Zehnder interferometer for biosensing.

Main Methods:

• Utilized surface plasmon spectroscopy, waveguide mode spectroscopy, and integrated optical Mach-Zehnder interferometry.
• Investigated various biotin-derivatives immobilized in monolayers for streptavidin affinity.
• Measured streptavidin layer density and optical constants of molecules.

Main Results:

• Characterized biotinylated monolayers and streptavidin binding using multiple optical techniques.
• Demonstrated the integrated optical Mach-Zehnder interferometer's sensitivity to antigen-antibody binding.
• Identified challenges in increasing sensitivity via fluorescence detection due to bleaching.

Conclusions:

• The integrated optical Mach-Zehnder interferometer shows promise as a reusable affinity sensor.
• Understanding binding matrix characteristics is essential for optimizing sensor performance.
• Further research is needed to overcome limitations for enhanced sensitivity.