▎ 摘　　要

NOVELTY - Forming polychromatic fluorescent polyetherimide (PEI) functionalized graphene quantum dots involves: dispersing graphene oxide sheet in ethanol/water at a concentration of 5-100 mg/10 ml of solution, adding ammonium hydroxide to regulate pH at 12, adding 0.2 plus minus 0.01 g PEI per 40 ml of solution, then transferring solution into reactor at 100-200 degrees C for 1-24 hours, naturally cooling, filtering to obtain stock solution; and drying stock solution over anhydrous sodium sulfate, purifying the product using gradient column chromatography, and collecting purified product. USE - For forming polychromatic fluorescent polyetherimide (PEI) functionalized graphene quantum dots (claimed) which are useful in optoelectronic materials, and for bio-imaging, and targeted drug delivery. ADVANTAGE - The present method is simple, easy to operate and cost-effective; and produces quantum dots in an increased yield of 18.1% with high purity as compared to reference quantum dots. DETAILED DESCRIPTION - Preparation of polychromatic fluorescent polyetherimide (PEI) functionalized graphene quantum dots involves: dispersing graphene oxide sheet in ethanol or water at a concentration of 5-100 mg/10 ml of solution, adding 25% ammonium hydroxide to regulate pH at 12, adding 0.2 plus minus 0.01 g polyetherimide (PEI) per 40 ml of solution, then transferring the solution into reactor at 100-200 degrees C for 1-24 hours, naturally cooling, filtering to obtain PEI functionalized graphene quantum dots stock solution; and drying the stock solution over greater than 99% anhydrous sodium sulfate, purifying the product by using gradient column chromatography, and collecting the purified product.