Functional optical fiber evanescent field sensor based on solid phase extraction and assembly method of functional optical fiber evanescent field sensor

Abstract

The invention discloses a functional optical fiber evanescent field sensor based on solid phase extraction and an assembly method of the functional optical fiber evanescent field sensor. The sensor comprises a light source, an optical fiber, a capillary tube, a photomultiplier tube detector and a liquid conveying unit, wherein an outer cladding layer on the surface at the left end of the optical fiber is retained, the outer cladding layer in the middle and at the right end are completely removed to expose the optical fiber core, the optical fiber core is inserted into the capillary tube and extends out of the capillary tube, both ends of a gap between the optical fiber core and the capillary tube are sealed, and a liquid flow cell is formed; a liquid inlet is formed in the left end side wall of the capillary tube, and a liquid outlet is formed in the right end side wall; an adsorption column is arranged on a liquid transport tube or an adsorption material layer is embedded in the surface of the optical fiber core in the flow cell, the light source is located on the left side of the optical fiber and coupled with the optical fiber, and a photomultiplier tube is arranged below the capillary tube to detect the change of evanescent field intensity. An analyte is pre-enriched on an adsorption material with a pre-enrichment technology, interference of a matrix is eliminated by the solid phase extraction, selectivity and sensitivity are also improved, and detection of the trace analyte is realized.

Description

technical field [0001] The invention belongs to the field of optical sensor devices, and in particular relates to a solid phase extraction functional optical fiber evanescent field sensor and an assembly method thereof. Background technique [0002] Optical fiber chemical sensor is a device that combines optical fiber with spectroscopic technology, transmits optical signals by means of optical fiber, and installs a signal generating layer on the end or surface of the optical fiber. The main body of the fiber structure is the core with a higher refractive index and the cladding with a lower refractive index, both of which play a decisive role in the propagation of light; total reflection is the working basis of the fiber, and it takes two Conditions: (1) Light is emitted from an optically denser medium to an optically rarer medium; (2) The incident angle is greater than or equal to the critical angle of total reflection. Optical fiber sensors have fast response speed, large ...

AI Technical Summary

Problems solved by technology

The light-transmitting fiber optic sensor will change the output light intensity because the light is absorbed by the medium, and the information of the object to be measured is reflected by detecting the change of the output light intensity. The light-transmitting fiber optic sensor has extremely high requirements for mechanical alignment precision, and the sensing distance limited, the structure of the sensor is complex, the production cost is high, and the stability is relatively poor

Images