A Fiber-Optic Fluorometric Immunoassay for Determination of Dermatophagoides Farinae Allergen (Der f1)

Abstract

Immunoassay methods are generally used for measuring of allergenic substances. However, they need special facilities, cumbersome manipulation and taking a lot of time to get results. In this work, rapid and easy immunoassay using optical fiber system was established, which detected fluorescence of an immune complex formed by allergen and fluorescently labeled antibody. The immune complex was bound at the optical fiber probe surface, and excitation light was transmitted into the probe. Then evanescent wave was generated and excited fluorescent molecules, finally, fluorescent light was detected by a photo diode. Dermatophagoides farinae allergen (Der f1) was measured and cyanine 5 (Cy5) was used as fluorescent molecule. The fiber-optic immunoassay could detect and quantify Der f1. The measurement range was from 1.95ng/ml to 250 ng/ml, and the result was the equivalent of ELISA. The measurement time was 15min/sample.