▎ 摘　　要

NOVELTY - Detecting thrombin based on graphene-quantum dot/erbium ion fluorescent nano probe comprises e.g. adding erbium(III) ion in the GQDs solution, where the graphene-quantum dots (GQDs) solution has good fluorescence emitting properties, and GQDs is set with surface carbonyl, carboxy, hydroxy and epoxy group e.g. oxygen-containing groups that are reactive with erbium(III) ion coordination effect to form GQDs/erbium(III) ion complex, thus shortening the distance between the GQDs, making the GQDs aggregation and fluorescence quenching, added thrombin to the binding site of GQDs/erbium(III) ion. USE - The method is useful for detecting thrombin based on graphene-quantum dot/erbium ion fluorescent nano probe (claimed). ADVANTAGE - The method can achieve recovery degree with the thrombin concentration proportional to the fluorescence of GQDs, does not need to functionally modify the surface of the GQDs, there is no need to use thrombin aptamer, and uses GQDs fluorescence switching transition that can realize sensitive and selective detection of thrombin. DETAILED DESCRIPTION - Detecting thrombin based on graphene-quantum dot/erbium ion fluorescent nano probe comprises adding erbium(III) ion in the GQDs solution, where the graphene-quantum dots (GQDs) solution has good fluorescence emitting properties, and GQDs is set with surface carbonyl, carboxy, hydroxy and epoxy group e.g. oxygen-containing groups that are reactive with erbium(III) ion coordination effect to form GQDs/erbium(III) ion complex, thus shortening the distance between the GQDs, making the GQDs aggregation and fluorescence quenching, added thrombin to the binding site of GQDs/erbium(III) ion, in which thrombin competes with GQDs/erbium(III) ion, separating the GQDs from GQDs/erbium(III) ion and dispersing in solution, resulting in GQDs fluorescence recovery, along with the increasing of the thrombin concentration, fluorescence of GQDs recovery degree is gradually increased, carrying out fluorescence intensity and the thrombin concentration of GQDs in linear relationship for sensitive and selective detection of thrombin; the GQDs is prepared by (i) adding 1 g carbon powder, 60 ml concentrated nitric acid and 180 ml concentrated sulfuric acid into a 250 ml reaction flask, ultrasonically processing for 2 hours, (ii) at 100% power ultrasound processing solution for 2 hours at 120 degrees C, diluting mixture by ultra-pure water to 800 ml, obtaining brown solution, neutralizing solution with sodium carbonate, pH is 7, concentrating, filtering to remove most sodium salt, dialyzing filtrate in 1000 Da dialysis bag for 3 days, obtaining product GQDs, dispersing GQDs in ultra-pure water.