Photonic Crystal Surface Mode Real-Time Imaging of RAD51 DNA Repair Protein Interaction with the ssDNA Substrate

Area of Science:

• Biophotonics and Nanotechnology
• Molecular Biology and Genetics
• Biomedical Engineering

Background:

• Photonic crystals (PCs) offer label-free sensing capabilities for analyzing molecular interactions.
• RAD51 protein is crucial for DNA repair and its overexpression correlates with aggressive cancers, making it a therapeutic target.
• Imaging PC surface modes enables multiplexed detection of binding events at the sensor interface.

Purpose of the Study:

• To design and validate a PC-based array sensor for real-time monitoring of oligonucleotide-RAD51 recruitment.
• To demonstrate the potential of surface mode imaging for sensitive, multiplexed analysis of biomolecular interactions.
• To establish a biosensor platform for drug discovery and identification of novel cancer therapeutic targets.

Main Methods:

• Development of a photonic crystal (PC) array sensor.
• Surface modification and decoration with recognition units for specific binding.
• Real-time monitoring using surface mode imaging.
• Microfluidic integration for sample delivery and analysis.

Main Results:

• The PC biosensor successfully monitored oligonucleotide-RAD51 recruitment in real-time.
• Achieved highly sensitive, multiplexed analysis of association-dissociation events.
• Demonstrated detection of a DNA damage biomarker using the microfluidic PC array.
• Validated the concept of surface mode imaging for biosensing applications.

Conclusions:

• The developed PC biosensor enables sensitive, real-time, multiplexed detection of biomolecular interactions.
• This technology holds significant potential for drug discovery, including screening candidate drugs and identifying new molecular targets.
• The biosensor platform can be adapted for high-content screening of novel DNA repair inhibitor drugs targeting RAD51.