Botulinum Neurotoxin C Dual Detection through Immunological Recognition and Endopeptidase Activity Using Porous...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Environmental Science

Background:

• Botulinum neurotoxins (BoNTs) from *Clostridium botulinum* cause severe diseases in animals, leading to significant economic losses and environmental concerns.
• Current *in vivo* mouse assays for BoNT detection are insufficient for timely, on-site outbreak assessment.

Purpose of the Study:

• To develop a novel reflective-based optical biosensor for the simultaneous detection and activity assessment of BoNT/C.
• To provide a sensitive, specific, and rapid diagnostic tool for animal botulism outbreaks.

Main Methods:

• Utilized two adjacent porous silicon Fabry-Pérot interferometers for a competitive immunoassay.
• Quantified BoNT/C concentration and assessed endopeptidase activity through amplified reflectivity signals.
• Validated specificity against BoNT/B and BoNT/D, and tested performance in complex media.

Main Results:

• Achieved a highly sensitive detection limit of 4.24 pg mL^-1 for BoNT/C, comparable to *in vivo* methods.
• Demonstrated excellent specificity and selectivity against related BoNT serotypes.
• Confirmed analytical performance in real-life scenarios using actual toxins in complex matrices.

Conclusions:

• The developed optical sensing scheme provides an efficient, rapid, and label-free approach for biodiagnostic elucidation of botulism.
• This technology holds potential for real-time, on-site monitoring and management of animal health emergencies caused by BoNTs.