Detection of Botulinum Neurotoxin by Tapered Fiber Optic Biosensor

Abstract

Botulinum neurotoxin (BoNT) is the most poisonous
protein known so far, with a minimal lethal dose of 1 ng/kg for
humans. Current in vitro detection methods for BoNTs are time
consuming and lack sensitivity. Our goal is to develop a highly
sensitive, label-free sensor for BoNT detection using tapered
fiber-optics biosensor (TFOBS) with an enhanced double-passes
detection system. Various protein immobilization methods for
glass surfaces were compared and antibodies for BoNT/A were
selected based on their specificity and sensitivity. The binding of
BoNT to the antibody immobilized on the fiber optics correlated
to the degree of spectral shift. The TFOBS, fabricated and
prepared in this study, was capable of measuring specific
antibody-antigen interactions in a concentration-dependent
manner and BoNT/A could be detected at as low as 50 ng/ml.
TFOBS is suitable to be developed into a highly sensitive
biosensor system for real-time, rapid, and label-free BoNT
detection.