Detection of Clostridium botulinum toxin A using a fiber optic-based biosensor

Area of Science:

• Analytical Chemistry
• Biotechnology
• Sensor Technology

Background:

• Clostridium botulinum toxin detection is crucial for public health and food safety.
• Existing methods for toxin detection can be time-consuming and complex.
• Development of rapid, sensitive, and specific detection methods is needed.

Purpose of the Study:

• To develop a rapid, sensitive, and specific analytical method for detecting Clostridium botulinum toxin.
• To utilize a fiber optic-based biosensor employing evanescent wave technology.
• To optimize antibody selection for enhanced assay performance.

Main Methods:

• A fiber optic probe with a tapered end was used, functionalized with antibodies specific for C. botulinum toxin.
• An argon-ion laser (514 nm) and rhodamine-labeled polyclonal anti-toxin A IgG antibodies facilitated signal generation via a sandwich immunoassay.
• Various anti-toxin antibodies were tested for immobilization, including affinity-purified polyclonal horse anti-toxin A and a monoclonal antibody.

Main Results:

• The developed fiber optic biosensor detected botulinum toxin within one minute.
• The method achieved a sensitivity of as low as 5 ng/ml.
• Affinity-purified polyclonal horse anti-toxin A antibodies demonstrated superior performance compared to other tested antibodies.
• The assay showed high specificity, with no cross-reactivity to tetanus toxin.

Conclusions:

• A rapid and sensitive fiber optic biosensor for Clostridium botulinum toxin detection has been successfully developed.
• The system offers a significant improvement in detection time and sensitivity.
• The optimized immunoassay using specific antibodies provides a highly selective detection platform.