Mycotoxin Biosensor Based on Optical Planar Waveguide.

Area of Science:

• Optoelectronics
• Biosensing Technology
• Analytical Chemistry

Background:

• Mycotoxins pose significant risks to food safety and human health.
• Existing biosensor technologies often face limitations in sensitivity, complexity, or cost.
• Development of rapid, sensitive, and cost-effective mycotoxin detection methods is crucial.

Purpose of the Study:

• To develop a simple and highly sensitive optical biosensor for mycotoxin detection.
• To utilize a planar waveguide with polarization interferometry for enhanced sensitivity.
• To demonstrate the sensor's capability for detecting ochratoxin A (OTA) at low concentrations.

Main Methods:

• Fabrication of a planar waveguide biosensor based on polarization interferometry.
• Utilizing the phase shift between p- and s-polarized light components upon analyte binding.
• Performing direct immunoassay for ochratoxin A (OTA) detection with immobilized antibodies.
• Characterizing the sensor's refractive index sensitivity and limit of detection.

Main Results:

• The developed biosensor operates on a simplified interferometer principle without waveguide splitting.
• Achieved high refractive index sensitivity of 5200 radians per refractive index unit (RIU).
• Successfully detected ochratoxin A (OTA) down to 0.01 ng/mL, demonstrating sensitivity at the part-per-trillion (ppt) level.

Conclusions:

• The proposed optical biosensor offers a simple yet highly sensitive platform for mycotoxin detection.
• The sensor's design and performance show potential for sensitive and rapid mycotoxin screening in various applications.
• Further development could enable detection of a wider range of mycotoxins at ultra-trace levels.