Zinc-doped carbon quantum dot, preparation method thereof and application thereof to detection field

Abstract

The invention provides a zinc-doped carbon quantum dot, a preparation method thereof and application thereof to the detection field. The carbon quantum dot high in quantum yield can be obtained through an environment-friendly simple one-step hydrothermal method by doping the zinc element for the first time, and the fluorescent quantum yield is high and can reach 63%. The preparation method specifically includes the steps that a carbon source and a zinc source are dissolved to obtain a precursor solution and placed into a hydrothermal reaction kettle to be reacted, after a synthesized product is naturally cooled, the product is separated to obtain a solution, the solution is dried, and the zinc-doped carbon quantum dot high in fluorescent quantum yield is obtained. Raw materials required by the method are few, intermediate products and side products are few, reaction speed is high, and the method is economical and environmentally friendly. The light emitting intensity of the zinc-doped carbon quantum dot is high and can reach 5.8*10<5>, the zinc-doped carbon quantum dot has wide application prospects as a fluorescent probe in biomedical detection, and the zinc-doped carbon quantum dot can be used for trace and quantitative analysis and detection of hydrogen peroxide and glucose.

Description

technical field [0001] The invention belongs to the field of nanomaterials, and relates to a zinc-doped carbon quantum dot, its preparation method and application thereof, in particular to a zinc-doped carbon quantum dot with high fluorescence quantum yield and luminous intensity, its preparation method and its application. Applications in the detection field. Background technique [0002] Rich in carbon element, it is the basis of all known life on earth. In 2004, Scrivens and others accidentally isolated carbon quantum dots when preparing single-walled carbon nanotubes by the purification arc discharge method in 2004, opening up a new era of new fluorescent sensitive materials. Research on carbon dots has developed rapidly. Luminescent carbon dots (Carbondots, CDs) are spherical nanoparticles with a carbon skeleton structure and a size less than 10 nm. Fluorescent carbon dots are one of the most popular carbon nanomaterials after fullerenes, carbon nanotubes and graphene...

AI Technical Summary

Problems solved by technology

The synthesis methods of carbon dots are mainly divided into "top-down" and "bottom-up". The "top-down" method of preparing carbon quantum dots often has the following disadvantages: special equipment is required, and the yield is low , destroying the crystal lattice, non-selective chemical cleavage is often unable to control the size and morphology of carbon quantum dots

The "bottom-up" methods mainly include hydrothermal method, microwave method, and high-temperature pyrolysis carbonization method. Among them, the hydrothermal method has the advantages of simplicity, quickness, and easy control of conditions, and its application is relatively mature, but there are still carbon quantum dots prepared. The disadvantage of low fluorescence quantum yield, which limits the application of carbon quantum dots to a certain extent

[0005] In recent years, in order to obtain carbon quantum dots with better performance, researchers have carried out surface modification or element doping on carbon quantum dots. The research mainly focuses on doping carbon quantum dots with non-metallic elements such as sulfur, nitrogen or selenium. , while there are few reports about carbon quantum dots with high quantum yield prepared by metal element doping, CN105219384A discloses a preparation method of yellow fluorescent carbon quantum dots doped with zinc ions, using zinc source, carbon source, passivating agent React with an organic solvent in a hydrothermal kettle, centrifuge, take the supernatant, and spin evaporate or dry to obtain a solid powder. The solid is ultrasonically dissolved in water and then dialyzed through a dialysis membrane to obtain an aqueous solution of carbon quantum dots. The obtained zinc ion-doped Miscellaneous yellow fluorescent carbon quantum dots have an amorphous structure and have excitation-independent characteristics. The main fluorescence emission peak is at 560-590nm, the fluorescence lifetime is 5-10ns, the diameter is 2-6nm, and the quantum yield is between 35-50%. , the quantum dots can stably emit yellow fluorescence. However, this method belongs to the solvothermal method, and the carbon quantum dots must be prepared by using a zinc source, a carbon source, a passivating agent and a specific organic solvent. The choice of solvent is highly dependent, and one of toluene, dimethyl sulfoxide or N,N-dimethylformamide must be used as a solvent. These organic solvents are very harmful to the human body, and will be harmful to the environment during preparation and use. Adverse effects, the use of organic solvents and the use of four raw materials will increase the cost of carbon quantum dots, and the product has poor water solubility

[0006] The use of organic solvents in the preparation process of the above solvothermal method not only harms the environment but also increases the cost of carbon quantum dots. Compared with the solvothermal method, the hydrothermal method has the advantages of green environmental protection and low preparation cost. The research on the preparation of zinc-doped carbon quantum dots with good water solubility, high luminous intensity and high fluorescence quantum yield is of great significance and practical application value.

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