▎ 摘　　要

NOVELTY - Preparing graphene quantum dot comprises adding pyrene into concentrated nitric acid (65 wt.%), condensing and refluxing at 80 degrees C for 24-48 hours, cooling to room temperature, adding excess deionized water and performing suction filtration using a filter membrane, adding deionized water repeatedly, filtering and washing until the pH is neutral, placing the reaction product in an vacuum oven and drying at 65-85 degrees C to obtain yellow powder of trinitropyrene, (ii) weighing and dissolving dry trinitropyrene and sodium sulfite in ethanol, stirring uniformly, transferring the solution to a polytetrafluoroethylene based reaction kettle, reacting at 180-210 degrees C for 10-12 hours and (iii) completing the high-temperature reaction, cooling to room temperature, filtering the reaction product using 0.22 mu m filter membrane to remove unreacted particles, purifying using column chromatography separation and drying to obtain the product. USE - The quantum dot is useful in detecting water content in organic solvents and cell imaging based on fluorescence changes. ADVANTAGE - The quantum dot: is hydrophobic.