▎ 摘　　要

NOVELTY - Preparing graphene quantum dot-MXene fluorescence sensor, comprises (i) obtaining mixed solution of citric acid, glutathione and histidine, evaporating to remove water, and heating to obtain Glu-His-GQDs solid powder, adding water and adjust pH to 7 to obtain Glu -His-GQDs solution, dialysis and vacuum drying; (ii) dissolving Glu-His-GQDs product in buffer solution to obtain Glu-His-GQDs suspension, adjusting the pH to 5, adding an activator, and incubating with stirring, adjusting pH value to 7.4, adding omethoate aptamer, stirring reaction and centrifuging, and obtaining supernatant of aptamer linker; (ii) adding MXene to a polytetrafluoroethylene reaction kettle, pass hydrogen fluoride, ultrasonicating for 3-8 hours, add absolute ethanol, continuing ultrasonication for 10-60 minutes, and drying to obtain MXene two-dimensional nanosheets, obtained by adding water MXene solution; and (iii) mixing MXene solution with aptamer linker plus buffer solution and allowing to stand. USE - The fluorescence sensor is useful for detecting the oxide dimethoate (claimed) and in environmental monitoring and food safety monitoring. ADVANTAGE - The fluorescence sensor has the characteristics of easy synthesis, low cost, high photostability and low toxicity, high sensitivity and high specificity to omethoate. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for graphene quantum dot-MXene fluorescence sensor prepared as mentioned above.