Fabry-Perot interference optical fiber biosensor based on the ECF for label-free DNA detection

Area of Science:

• Biomedical Engineering
• Optoelectronics
• Nanotechnology

Background:

• Label-free DNA detection is crucial for rapid diagnostics.
• Existing biosensors face challenges in sensitivity and stability.
• Fiber-optic sensors offer potential for high-resolution detection.

Purpose of the Study:

• To develop a self-reference fiber-optic biosensor for label-free DNA detection.
• To enhance the stability and resolution of DNA detection systems.
• To evaluate the sensitivity and selectivity of the proposed biosensor.

Main Methods:

• Fabrication of a parallel Fabry-Perot interference (FPI) structure using exposed core fiber (ECF) and standard/multimode fiber (SMF/MMF).
• Implementation of a self-reference differential phase demodulation technique utilizing the ECF air cavity.
• Functionalization of the fiber surface for complementary DNA (cDNA) capture and testing with non-complementary DNA (N-cDNA).

Main Results:

• The biosensor demonstrated a linear response within the 1 to 5 µM concentration range.
• Achieved a high sensitivity of 5.53°/µM.
• The limit of detection was as low as 1 µM, indicating excellent performance.

Conclusions:

• The proposed self-reference fiber-optic DNA biosensor offers high sensitivity and selectivity.
• The differential phase demodulation technique significantly improves system stability and resolution.
• This technology holds promise for advancements in biomedical diagnostics, environmental monitoring, and food safety.