Fluorescent carbon quantum dot as well as preparation method and application thereof

Abstract

The invention provides a fluorescent carbon quantum dot which is high in fluorescent quantum yield and a preparation method of the fluorescent carbon quantum dot. The preparation method of the fluorescent carbon quantum dot comprises the following steps: by taking oxalic acid as a carbon source and urea as a nitrogen source, adding secondary water to perform ultrasonic treatment to obtain a clear solution; putting the clear solution in a microwave oven to react to finally obtain light yellow solids; taking out the light yellow solids to be naturally cooled, then, adding a certain amount of secondary water, and stirring and dissolving to obtain a light yellow solution, removing insoluble substances to obtain a clear light yellow solution, dialyzing to remove impurities to obtain a carbon quantum dot solution, and freezing and drying to obtain a carbon quantum dot. The preparation method disclosed by the invention is simple in process, wide in raw material source, low in price, low in requirements of preparation conditions, and relatively high in quantum yield of the obtained quantum dot. The carbon quantum dot obtained by the preparation method disclosed by the invention can be used for detecting Fe<3+> and Ag<+> in water, can be applied to living cell fluorescence imaging and also can be used as a false proof mark.

Description

technical field [0001] The invention relates to a luminescent nanometer material, in particular to a carbon quantum dot, in particular to a carbon quantum dot with a high fluorescence quantum yield and a preparation method and application thereof. Background technique [0002] Carbon quantum dots (carbon dots, C-dots) are a carbon-based material first discovered by Scrivens et al. It is a new nanomaterial with a skeleton structure. Compared with traditional semiconductor quantum dots and organic dyes, carbon quantum dots, as a new type of luminescent material, not only maintain the advantages of carbon materials such as low toxicity and good biocompatibility, but also have the advantages of synthetic Convenience, easy modification, adjustable luminous range, large two-photon absorption cross section, high fluorescence quantum efficiency, good photostability, no light flicker, easy functionalization, low price, easy large-scale synthesis and other incomparable advantages, and...

AI Technical Summary

Problems solved by technology

The top-down synthesis method, that is, the physical method of exfoliating carbon nanoparticles from larger carbon structures, and then passivating the polymer surface to make them emit light effectively, mainly includes arc discharge, laser ablation, and electrochemical oxidation. , electron beam radiation, etc., such methods often require strict experimental conditions or special energy sources, the cost is high, and the fluorescence quantum yield of carbon quantum dots is low; the bottom-up synthesis method, that is, through pyrolysis or carbonization Suitable precursors directly synthesize fluorescent carbon quantum dots, including combustion method, hydrothermal carbonization method, supported synthesis method, microwave method, ultrasonic method, etc., but because the raw materials selected by this type of method are all non-renewable energy sources and require strict post-processing technology, so it is not conducive to the continuous and large-scale production of carbon quantum dots

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