▎ 摘　　要

NOVELTY - Dual-channel probe type 81 degrees tilted fiber grating sensor system comprises broadband light source (1), optical isolator (2), online polarizer (3), dual-channel sensor (4) and spectrum analyzer (5) connected in sequence. The dual-channel sensor includes a 22 coupler and two polarization controllers respectively connected, each polarization controller is also connected with a reflective 81 degrees TFG probe. The reflective 81 degrees TFG probe passes through 22 other port of the coupler which is connected with the spectrum analyzer. The end surface of the reflective 81 degrees TFG probe is plated with a silver reflective film, and the surface of the grid region of the reflective 81 degrees TFG probe is fixed with a nano-gold shell particle layer through covalent bonds, and the surface of the nano-gold shell particle layer A graphene oxide film is adsorbed, and a specific biological recognition molecule is immobilized on the surface of the graphene oxide film through a covalent bond. USE - Dual-channel probe type 81 degrees tilted fiber grating sensor system used in immunodetection of alpha-fetoprotein, where the specific biorecognition molecule is alpha -fetoprotein (AFP) monoclonal antibody (claimed). ADVANTAGE - The dual-channel probe type 81 degrees tilted fiber grating sensor system realizes the simultaneous detection of the positive and negative samples of the target biomolecule, enhances the reliability of its clinical detection application or simultaneously specific for two different target biomolecules, is easy to perform detection, rapid detection, simple operation and probe-type structure operation is more convenient, and has great application potential. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a dual-channel probe type 81 degrees tilted fiber grating sensor system, which involves: (A) taking 81 degrees TFG and cutting a flat end face 1~2cm away from the end of the grid area, and plating a layer of reflective film on the end face to obtain a pretreated 81 degrees TFG; (B) immersing the pretreated 81 degrees TFG into the sodium hydroxide solution to activate the hydroxyl groups on the surface of the fiber, and immersing the hydroxylated gate area in the silane coupling agent, and keeping at 65 degrees C to introduce sulfhydryl groups on the surface of the fiber, immersing in the centrifugal gold nanoshell solution to make the gold nanoshell covalently bond to the surface of the gratin, surface of the grating is repeatedly washed with ultrapure water and dried to make an 81 degrees TFG-LSPR probe; (C) placing 81 degrees TFG- long period fiber grating (LPFG) probe in the graphene oxide dispersion solution for 6 hours, and depositplacing the graphene oxide film on the surface of the grating, immersplacing in the 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) activator to activate the carboxyl groups on the surface of the graphene oxide, and rinsing the surface with ultrapure water and absolute ethanol to obtain the 81 degrees TFG-LSPR-GO probe; (D) taking two 81 degrees TFG-LSPR-graphen oxide (GO) probes and respectively immersing in a biomolecule solution that specifically recognizes the target analyte to react, so that the biomolecules are covalently bonded to the surface of graphene oxide, washing repeatedly with phosphate buffer solution, and immersing in the skimmed milk powder blocking solution to seal the unbound carboxyl sites on the GO surface to obtain two reflective 81 degrees TFG probes; and (E) connecting each portion in the order of broadband light source, optical isolator, online polarizer, 22 coupler, two polarization controllers, two reflective 81 degrees TFG probes and spectrum analyzer. DESCRIPTION OF DRAWING(S) - The drawing shows schematic view of dual-channel probe type fiber grating sensor system. Light source (1) Optical isolator (2) Online polarizer (3) Dual-channel sensor (4) Spectrum analyzer (5)