Detection of Botulinum Neurotoxin by Tapered Fiber Optic Biosensor
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.