▎ 摘　　要

NOVELTY - A mesoporous material coated carbon fiber is prepared by: (1) calcining tow carbon fiber base material at 400-500degrees Celsius for 0.5-2 hours, washing 3-5 times with acetone, ethanol and deionized water, naturally drying, paving the processed carbon fiber in a quartz boat, uniformly bombarding the surface of the carbon fiber by using a plasma at 50-100 W and an oxygen flow rate of 120-80 ml/minute for 15-90 seconds; and (2) soaking the processed carbon fiber in a mesoporous material for 10-15 hours, soaking for 3-10 minutes under the action of ultrasonic waves, taking out, and calcining for 2.5-3.5 hours. USE - The mesoporous material coated carbon fiber is useful in nano-silver/nitrogen doped carbon film/carbon fiber, nano-silver/graphene quantum dot/carbon fiber, and nano-silver/carbon film/carbon fiber, which is useful in preparation of electrochemical sensor used for simultaneous detection of dopamine, ascorbic acid and uric acid (all claimed) in food, blood sample, and environmental sample such complex matrix sample. ADVANTAGE - The mesoporous material coated carbon fiber prepares carbon fiber electrode, which improves detection range, sensitivity, anti-interference and anti-pollution capability of the electrochemical sensor, and reduces the detection limit. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a nano silver/nitrogen doped carbon film/carbon fiber prepared by adding 0.1 M potassium nitrate and 0.1-2 g pyrrole monomer, taking the mesoporous material coated carbon fiber as a working electrode, electrodepositing at 1-7 V for 30-300 seconds to prepare a polypyrrole film, placing in a corundum boat, carbonizing at 400-900degrees Celsius to obtain a nitrogen-doped carbon film/carbon fiber, taking the nitrogen-doped carbon film/carbon fiber as a working electrode, adding silver nitrate to 0.1 M potassium nitrate electrolyte, and scanning in 5-15 cycles by cyclic voltammetry at -0.8 V to 1 V and 25 mV/second; (2) a nano silver/graphene quantum dot/carbon fiber, which is prepared by taking the plasma-treated carbon fiber electrode as a working electrode, silver/silver chloride as a reference electrode, and platinum as an electrode standard three-electrode system, adding graphene quantum dot aqueous dispersion solution to 0.01 M phosphate-buffered saline (PBS) buffer solution with pH of 7.4, scanning in 5-15 cycles by cyclic voltammetry at -2 V to 2 V and 25 mV/second, depositing graphene quantum dots on the surface of the material, taking graphene quantum dot carbon fiber as working electrode, adding a preset amount of silver nitrate to 0.1 M potassium nitrate electrolyte, scanning 5-15 circles by cyclic voltammetry at -0.8 V to 1 V and 25 mV/second, and depositing silver nanoparticles on the surface of the material; and (3) a nano silver/carbon film/carbon fiber, which is prepared by taking the nitrogen-doped carbon film/carbon fiber as a working electrode, silver/silver chloride as a reference electrode, and platinum as an electrode standard three-electrode system, adding the graphene quantum dot aqueous dispersion solution to 0.01 M PBS buffer solution with pH of 7.4, scanning 5-15 circles by cyclic voltammetry at -2 V to 2 V and 25 mV/second, depositing graphene quantum dots on the surface of the material, taking the graphene quantum dot carbon fiber as working electrode, adding silver nitrate to 0.1 M potassium nitrate electrolyte, scanning in 5-15 cycles by cyclic voltammetry at -0.8 V to 1 V and 25 mV/second, and depositing silver nanoparticles on the surface of the material.