▎ 摘　　要

NOVELTY - Single-layer monocrystalline graphene quantum dot has hexagonal grid striped single crystal structure. USE - Single layer monocrystalline graphene quantum dot (claimed). ADVANTAGE - The single layer monocrystalline graphene quantum dot has bright fluorescence. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the quantum dot, which involves mixing polycyclic aromatic hydrocarbon and acid at -5 degrees C to 5 degrees C for 0.5-2 hours, adding oxidant and stirring for 0.5-2 hours to obtain a mixture, reacting the mixture obtained in an oil bath at 60-100 degrees C for 1-5 hours and placing the reaction product in deionized water to obtain a suspension, filtering the suspension obtained with a microfiltration membrane, adjusting the pH of the filtrate to 6-8 with a basic compound, and dialyzing for 1-5 days to obtain a single layer graphene quantum dot solution, and drying the obtained solution to remove water.