▎ 摘　　要

NOVELTY - Preparing sulfur doped graphene quantum dot comprises taking carbon source compound and sulfur source compound dissolving into water, carrying out hydro-thermal reaction, to obtain sulfur doped graphene quantum dot, where the carbon source compound is 1,3,6-trinitro pyrene and the sulfur source compound is 3-4C mercapto fatty acid. USE - The sulfur doped graphene quantum dot is useful for detecting of silver ions (claimed). ADVANTAGE - The method can demonstrate the synthesis of higher quality sulfur doped graphene quantum, silver ion has obvious selective recognition ability for fast detection of trace amounts of silver ions. The sulfur doped graphene quantum dot has good fluorescent property, has stable fluorescence emission time when the pH value is not less than 4, a stable fluorescence emission; when used with a 320-360 nm excitation wavelength excitation fluorescence emission peak excitation wavelength-independent, position does not change. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for sulfur doped graphene quantum dot is prepared by the above mentioned method.