An Optical Universal Plasmon-Based Biosensor for Virus ‎‎Detection

Area of Science:

• Optics and Photonics
• Biomedical Engineering
• Materials Science

Background:

• Kretschmann configuration is a subwavelength framework for detecting refractive index changes in biomaterials.
• Traditional assessments often rely on plane wave excitation transfer matrix methods (TMM), which may lack accuracy for complex simulations.
• A more robust theoretical framework is needed for precise evaluation of plasmonic biosensors.

Purpose of the Study:

• To adapt a reformulated Fast Fourier Transform Beam Propagation Method (FFT-BPM) for theoretical assessment of surface plasmonic waveguide biosensors.
• To provide a more accurate and reliable simulation framework compared to the plane wave approximation.
• To evaluate the performance characteristics of the proposed biosensor design.

Main Methods:

• Excitation of surface plasmon mode using a sub-wavelength narrow light beam.
• Utilizing the highly confined optical energy of the plasmonic mode for sensitive detection of analyte composition variations.
• Electronic detection of plasmonic guided power via an optical MOS capacitor.

Main Results:

• The guided plasmonic power was used to assess sensor performance.
• Key characteristics evaluated include linearity, sensitivity, figure of merit, and full width at half maximum (FWHM).

Conclusions:

• The proposed sensor offers integration with angular measurement systems (e.g., goniometers) or electronic detection.
• This work is valuable for researchers and developers of sensitive biosensors, particularly when complex analysis tools are undesirable.