Authors: Zhijing (Jennifer) Guo, Chris Boyter, Greg Cohoon, Ertan Salik, and Wei-Jen Lin
Botulinum neurotoxin (BoNT), a Category A Biodefense agent, is the most poisonous protein known so far, with a minimal lethal dose of 1 ng/kg for humans and animals. Current in vitro detection methods for BoNTs are time consuming and lack of sensitivity. Biosensor technologies developed recently for various pathogens and toxins are promising for a highly sensitive, fast, real-time and local detection system for BoNTs. 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 surface were compared and antibodies for BoNT/A were selected based on their specificity and sensitivity determined by ELISA. The TFOBS, fabricated and prepared in this study, was capable of measuring specific antibody-antigen interactions at a concentration-dependent manner and BoNT/A could be detected at as low as 50 ng/ml. TFOBS is suitable to be developed into highly sensitive biosensor system for real-time, rapid, and label free BoNT detection.
Keywords: botulinum neurotoxin, fiber-optic biosensor, tapered