▎ 摘　　要

NOVELTY - Graphene quantum dot immunochromatographic test strip comprises sample pad (1), quantum dot mark binding pad (2), nitrocellulose membrane coated with antibody (3), detection line T line (4), quality control line C line (5), bottom plate (6) and absorbent paper (7). The sample pad, the quantum dot label binding pad, the antibody-coated nitrocellulose membrane, and the absorbent paper are sequentially pasted on the bottom plate. USE - The strip is useful for rapid detection of Escherichia coli O157:H7. ADVANTAGE - The strip has biological active protein-antibody, can indicate the binding reaction condition of the antigen antibody, and detecting sensitivity 10 colony-forming unit (CFU)/ml. DETAILED DESCRIPTION - Graphene quantum dot immunochromatographic test strip comprises sample pad (1), quantum dot mark binding pad (2), nitrocellulose membrane coated with antibody (3), detection line T line (4), quality control line C line (5), bottom plate (6) and absorbent paper (7). The sample pad, the quantum dot label binding pad, the antibody-coated nitrocellulose membrane, and the absorbent paper are sequentially pasted on the bottom plate. The method for preparing the quantum dot mark bonding pad is: (i) taking polyacrylonitrile (PAN)-based carbon fiber as a carbon source, treating at 500-550 degrees C for 1-1.5 hours, removing the sizing agent on the surface of PAN-based carbon fiber, utilizing stainless steel clips to fix 78 to 80 bundles of carbon fibers that remove the sizing agent on the surface of PAN-based carbon fibers as anodes, (ii) taking 1 mol/l ammonium carbonate aqueous solution as electrolyte, titanium mesh as cathode, and carrying out electrochemical reaction for 12-13 hours under constant voltage of 20-25 V, (iii) heating electrolytic solution and decomposing at 100 degrees C for 4-4.5 hours to remove ammonium carbonate in the electrolyte, (iv) filtering with 0.1 mu m filter membrane and dialyzing the filtrate for three days with a dialysis bag to obtain a GQDs solution, sequentially adding 100 mg/ml 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride aqueous solution and 100 mg/ml N-hydroxy to 1 ml GQDs solution, allowing to stand at room temperature for 2-2.5 hours, adding 10 mu g Escherichia coli O157:H7 wall protein monoclonal antibody, allowing at stand at room temperature for 4 hours, centrifuging at 4 degrees C for concentration, discarding the supernatant, adding 400 mu l resuspension and mixing evenly, spraying evenly on the bonding pad, spraying concentration of 10 mu l/cm2, drying at 37 degrees C, and ventilating. The resuspension is 3 wt.% protein protector trehalose, 0.5 wt.% bovine serum albumin, 1 wt.% stabilizer PEG20000, 1 wt.% suspending agent PVP, and phosphate buffered saline (remaining amount). The method for preparing the antibody-coated nitrocellulose membrane 3 is: coating the coating solution on the nitrocellulose membrane, the coating amount is 1 mu l/cm, and drying at 37 degrees C for 30 minutes to obtain the nitric acid coating antibody fiber membrane 3. The coating solution is a mixed solution composed of a different Escherichia coli O157:H7 wall protein monoclonal antibody dissolved in 0.01 mol/l phosphate buffer, the concentration of Escherichia coli O157:H7 wall protein monoclonal antibody is 1 mg/ml. The preparation method of the detection line T line 4 and the quality control line C line 5 is: diluting the Escherichia coli O157:H7 viable monoclonal antibody with phosphate buffered saline solution with a concentration of 0.01-0.8 mg/ml, diluting the secondary antibody to 0.2 mg/ml, mixing well, shaking well, allowing to stand still, taking 100 mu l and placing sample on the nitrocellulose membrane 3 as the detection line and the quality control line respectively, and drying at 37 degrees C. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the strip. Sample pad (1) Quantum dot mark binding pad (2) Nitrocellulose membrane coated with antibody (3) Detection line T line (4) Quality control line C line (5) Bottom plate (6) Absorbent paper (7)