▎ 摘　　要

NOVELTY - Preparation of nano-titanium dioxide/reduced graphene composite modified electrode includes dissolving titanium sulfate in water, mechanically stirring, reacting, centrifuging, washing with pure water and ethanol, and vacuum drying to obtain nano-titanium dioxide; dispersing graphene oxide in distilled water, ultrasonically dispersing, centrifuging, and collecting graphene oxide solution; adding nano-titanium dioxide to graphene oxide solution, and ultrasonically dispersing to obtain titanium dioxide-graphene oxide dispersion; polishing glassy carbon electrode with alumina polishing powder, adding to distilled water, washing with absolute ethanol and with distilled water, and drying; and dispersing titanium dioxide-graphene oxide droplets on surface of glassy carbon electrode, drying to obtain modified electrode used as working electrode, taking saturated calomel electrode as reference electrode and platinum wire electrode as counter electrode, and inserting to phosphate buffer. USE - The method is for preparation of nano-titanium dioxide/reduced graphene composite modified electrode for detection of lemon yellow in beverages. ADVANTAGE - The modified electrode has stable performance and strong anti-interference ability. DETAILED DESCRIPTION - Preparation of nano-titanium dioxide/reduced graphene composite modified electrode comprises: (A) dissolving 10-20 pts. wt. titanium sulfate in 75-85 pts. wt. water, mechanically stirring for 35-45 minutes, transferring to reactor, reacting to 165-175 degrees C for 5-6 hours, centrifuging at speed of 15000 revolutions/minute for 5 minutes, washing with pure water and ethanol, and vacuum drying to 45-55 degrees C to obtain nano-titanium dioxide; (B) dispersing 10-20 pts. wt. graphene oxide in 90-100 pts. wt. distilled water, ultrasonically dispersing for 3-4 hours, centrifuging for 3 times removing precipitate, and collecting supernatant to obtain graphene oxide solution; (C) adding 5-15 pts. wt. nano-titanium dioxide to 25-35 pts. wt. graphene oxide solution, and ultrasonically dispersing for 3-4 hours to obtain titanium dioxide-graphene oxide dispersion; (D) polishing glassy carbon electrode with 0.05 mu m alumina polishing powder, adding to distilled water, washing with absolute ethanol and with distilled water every 2-4 minutes, and drying; and (E) dispersing titanium dioxide-graphene oxide droplets on surface of glassy carbon electrode, drying through infrared lamp to obtain modified electrode used as working electrode, taking saturated calomel electrode as reference electrode and platinum wire electrode as counter electrode, inserting to 0.1 mol/L phosphate buffer having pH of 6, and reacting at - 1.4 V constant potential for 130-150 seconds.