Method for detecting golden glucose coccus by using immune optical-fiber evanescent-wave biosensor

Abstract

The invention discloses a method for detecting golden glucose coccus by using an immune optical-fiber evanescent-wave biosensor. The method comprises the following steps: (1) gluing a silver reflecting layer and coating a golden glucose coccus antibody on an optical-fiber probe of an immune optical-fiber evanescent-wave biosensor; (2) preparing a CdTe-polyclonal antibody conjugate, and making an aqueous solution; (3) inserting the optical-fiber probe capturing the antibody into a solution to be detected, then putting the optical-fiber probe capturing the antibody into the aqueous solution made from the CdTe-polyclonal antibody conjugate, and using the optical-fiber evanescent-wave biosensor for detecting. A 530nm semiconductor laser device is adopted, and a convex lens is arranged at the laser transmitting end of the laser device. The method solves the problem that when a terminal incidence angle of parts of light is smaller than a critical angle, the light is transmitted into the solution, and a fluorescent signal is lost. The detection limit and detection sensitivity of an optical-fiber biosensor system are improved, and the limit of detection of the golden glucose coccus is increased to 5ng / mL.

Description

technical field [0001] The invention belongs to the technical field of inspection and quarantine, and in particular relates to a method for detecting Staphylococcus aureus by an immune optical fiber evanescent wave biosensor. Background technique [0002] The optical fiber evanescent wave biosensor excites the fluorescent signal through the evanescent wave field. When light propagates in an optical fiber with total reflection, it can still generate waves that partially penetrate the interface, and the wave amplitude decays exponentially with the increase of the distance from the interface, so it only exists in a thin layer near the interface, called evanescent wave . Fluorescent immune fiber optic biosensors based on evanescent wave field excitation are a kind of fluorescent biosensors. It mainly combines the characteristics of the evanescent wave field generated when light propagates in the optical fiber and the high specificity and high sensitivity of the antibody-antige...

AI Technical Summary

Problems solved by technology

Since the inner diameter of the optical fiber itself can generally reach 200 μm, part of the fluorescence is bound to be emitted from the optical fiber during the fluorescence coupling process. The larger the cone length, the closer the incident angle is to the critical angle, but there are still some rays at the end whose incident angle is smaller than the critical angle. angle, so the propagating light is transmitted into the solution, and an absolute evanescent wave conduction environment cannot be formed.

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