Preparation method of carbon quantum dot fluorescent probe for detecting paraquat

Abstract

The invention relates to a preparation method of a carbon quantum dot fluorescent probe for detecting paraquat. The preparation method comprises the following two steps of firstly, accurately weighing0.03g of m-phenylene diamine, putting into anhydrous ethanol, dissolving, transferring into a hydrothermal reaction kettle with a polytetrafluoroethylene inner container, sealing, reacting for 12h ina constant-temperature drying box of which the temperature is increased to 160 DEG C by programs, naturally cooling to room temperature, fetching out, and putting the product into a beaker; adding anextender into the beaker, separating by a chromatography method, dialyzing the product by a dialysis bag, and diluting the remaining liquid by deionized water, so as to obtain the carbon quantum dotfluorescent probe with surface containing hydroxyl groups and carboxyl groups. The carbon quantum dot fluorescent probe has the advantage that when the spaces of the carbon quantum dot fluorescent probe with surface negative charges and the target molecule paraquat with positive charges are mutually approached under the mutual electrostatic function of cations and anions, the fluorescence resonance energy transfer is generated, the fluorescence intensity of the carbon quantum dot fluorescent probe is reduced, and the selective identification and sensitivity detection on the target molecule paraquat are realized.

Description

technical field [0001] The invention relates to the field of material science, in particular to a preparation method of a carbon quantum dot fluorescent probe capable of detecting paraquat. Background technique [0002] Paraquat, whose chemical name is 1-1-dimethyl-4-4-bipyridine cationic salt, is a fast-killing herbicide with contact and certain systemic effects. It can be quickly absorbed by the green tissue of plants, causing them to die. Paraquat is extremely toxic to humans, and the lethal dose for adults is 5-15 ml (20-40 mg / kg) of 20% aqueous solution, and there is no specific antidote, and the mortality rate of oral poisoning can reach more than 90%. At present, it has been banned or strictly restricted by more than 20 countries. With the wide application of herbicides, paraquat residue poisoning has become more and more common, and has become a common pesticide poisoning after acute organophosphate poisoning, and the number of poisoned people is increasing year by...

AI Technical Summary

Problems solved by technology

The CdTe quantum dot fluorescent probe prepared by this process is relatively cumbersome, and the CdTe quantum dot itself has Cd 2+ Ions are easily dissociated and released on the surface of quantum dots to produce toxicity. This effect is more obvious in oxidative environments and ultraviolet radiation, and external conditions and some properties of quantum dots themselves will affect the stability of quantum dots. Fluorescence is easy to bleach , easy to cause secondary pollution to the environment

[0013] It can be seen that the quantum dot fluorescent probes prepared in the above methods have defects and deficiencies, and are far less convenient than carbon quantum dot fluorescent probes.

At the same time, there is no report on the detection of paraquat by carbon quantum dot fluorescent probes. Therefore, the synthesis of highly selective and highly sensitive carbon quantum dot fluorescent probes rich in hydroxyl and carboxyl groups can easily and conveniently detect trace amounts of paraquat. It is necessary to identify and detect dry molecules

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