1D topological photonic crystal based nanosensor for tuberculosis detection.

Area of Science:

• Nanoscience and Nanotechnology
• Photonics and Optical Sensors
• Biomedical Diagnostics

Background:

• Development of highly sensitive biosensors is crucial for early disease detection.
• Topological photonic crystals (PCs) offer unique properties for light manipulation and sensing applications.
• Existing PC-based sensors face challenges in sensitivity and limit of detection.

Purpose of the Study:

• To design and investigate a nanosized biosensor utilizing one-dimensional (1D) topological photonic crystals.
• To compare the sensing performance of random-based and heterostructure-based topological PCs.
• To evaluate the potential of this biosensor for tuberculosis diagnosis based on refractive index changes.

Main Methods:

• Fabrication of 1D topological PCs using alternating Si and SiO2 layers.
• Design of topological structures by combining two distinct PC configurations (PC 1 and PC 2).
• Numerical simulation using the transfer matrix approach to analyze sensor performance.
• Optimization of layer thicknesses, number of periods, and incident angle for enhanced sensitivity.

Main Results:

• The random-based topological PC exhibited superior analyte sensing performance compared to the mirror heterostructure-based PC.
• The biosensor demonstrated significant blue shifts in photonic media due to analyte refractive index variations.
• Optimized sensor achieved a high sensitivity of 1500 nm/RIU, a low limit of detection of 2.2 × 10^-6 RIU, and a quality factor of 30,659.54.

Conclusions:

• Nanosized 1D topological photonic crystals are effective for developing highly sensitive biosensors.
• Random-based topological PCs offer enhanced analyte detection capabilities over heterostructure designs.
• The developed biosensor shows great promise for sensitive and accurate tuberculosis diagnosis.