Nitrogen doped graphene quantum dots as well as preparation method and application thereof

Abstract

The invention discloses nitrogen doped graphene quantum dots as well as a preparation method and application thereof in detecting mercury ions and cysteine and belongs to the technical field of fluorescence sensation. The preparation method comprises the following steps: dissolving a carbon source compound and a nitrogen source compound into water so as to obtain a mixed water solution, and performing a hydrothermal reaction under an alkali condition, so as to obtain the nitrogen doped graphene quantum dots, wherein the carbon source compound is 1,3,6-trinitropyrene; the nitrogen source compound is tryptophan; and the alkali condition is adjusted by using sodium hydroxide. The preparation method is high in yield, and gram-grade synthesis can be achieved at one time. Due to doping of high-content nitrogen atoms, the prepared nitrogen doped graphene quantum dots have glue fluorescence and have unique mercury ion selectivity. On the basis of quenching of mercury ions upon fluorescence ofthe nitrogen doped graphene quantum dots, sensitive fluorescence detection on the mercury ions can be achieved, and the detection limit is low. As the fluorescence quenched by the mercury ions can berecovered by using the cysteine, fluorescence detection on the cysteine can be achieved with the combination of the nitrogen doped graphene quantum dots and the cysteine.

Description

technical field

[0001] The invention relates to the technical field of fluorescence sensing, in particular to a nitrogen-doped graphene quantum dot, a preparation method thereof, and an application in fluorescence detection of mercury ions and cysteine. Background technique

[0002] Small molecules play crucial roles in various physiological and pathological processes. For example, mercury ions (Hg 2+ ) is one of the most toxic pollutants, which poses a great threat to the environment and human health. It can be converted into more toxic methylmercury through microbial methylation, and then accumulate in organisms through the food chain. Even at low concentrations of Hg intake 2+ It can also damage the nervous, endocrine and other systems, which can lead to many fatal diseases, such as headaches, kidney failure, mental loss, etc. As one of the essential amino acids in the human body, cysteine ​​has important physiological functions in nerve tissue, metabolism and detoxifi...

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