Inhibited coupling guiding hollow fibers for label-free DNA detection

Area of Science:

• Photonics and Nanotechnology
• Biomedical Engineering
• Biosensing

Background:

• Label-free biosensing is crucial for real-time molecular detection.
• Hollow-core fibers offer unique light-matter interaction properties.
• Existing DNA detection methods often require complex setups or labels.

Purpose of the Study:

• To numerically investigate the potential of hollow core tube lattice fibers for label-free DNA detection.
• To demonstrate a sensing mechanism based on inhibited coupling and transmittance changes.
• To assess the sensitivity and robustness of the proposed fiber-based sensing approach.

Main Methods:

• Numerical simulation of light propagation in hollow core tube lattice fibers.
• Modeling of bio-layer formation on the fiber's internal surface upon DNA hybridization.
• Analysis of transmission spectrum shifts in response to bio-layer thickness variations.

Main Results:

• The proposed fiber sensor exhibits high spectral sensitivity, with shifts up to 42 nm per 10 nm of bio-layer.
• The sensing mechanism relies on changes in the fiber's transmission spectrum due to bio-layer-induced refractive index changes.
• The approach demonstrates robustness against imperfect fiber coupling, a common challenge in optical fiber sensing.

Conclusions:

• Hollow core tube lattice fibers provide a promising platform for label-free DNA detection.
• The simple transmittance measurement technique eliminates the need for external transducers or amplification.
• This method is adaptable for sensing other complex molecular structures based on layer formation.