A Phase-Intensity Surface Plasmon Resonance Biosensor for Avian Influenza A (H5N1) Detection

Area of Science:

• Biomedical Engineering
• Optoelectronics
• Biosensing Technology

Background:

• Surface Plasmon Resonance (SPR) is a label-free optical technique widely used for detecting biomolecular interactions.
• Traditional SPR methods can be complex, requiring interference fringe analysis or phase extraction.
• Avian Influenza A (H5N1) poses a significant public health threat, necessitating sensitive and rapid diagnostic tools.

Purpose of the Study:

• To develop and validate a novel phase-intensity SPR biosensor for sensitive avian influenza A (H5N1) antibody detection.
• To demonstrate the biosensor's capability for label-free, real-time detection without complex data processing.
• To compare the performance of the developed biosensor against existing commercial systems.

Main Methods:

• A phase-intensity SPR biosensor was designed utilizing the steep phase change at SPR excitation between p- and s-polarized light.
• The sensor head was integrated with polarizers to detect intensity variations corresponding to polarization ellipse rotation.
• Refractive index sensing and H5N1 antibody detection experiments were conducted to evaluate sensor resolution and sensitivity.

Main Results:

• The biosensor achieved a resolution of 6.3 × 10^-6 refractive index units (RIU) in refractive index sensing.
• For H5N1 antibody detection, the sensor demonstrated a resolution of 193.3 ng mL^-1.
• This represents a significant improvement in detection limit compared to commercial Biacore systems (517.3% and 258.7% better).

Conclusions:

• The developed phase-intensity SPR biosensor provides a sensitive, real-time, and label-free method for H5N1 antibody detection.
• The simplified detection mechanism avoids complex data analysis, making it user-friendly.
• This technology holds significant promise for improved influenza diagnostics and surveillance.