Chemical preparation method for CdTe quantum dot fluorescent probe for detecting trace amount of paraquat

Abstract

A chemical preparation method for a CdTe quantum dot fluorescent probe for detecting a trace amount of paraquat comprises the step of modifying thioglycollic acid on the surface of the CdTe quantum dot fluorescent probe emitting a red emission spectrum band so as to enable the CdTe quantum dot fluorescent probe is provided with carboxyl functional groups on the surface. The preparation process comprises the following two specific steps: firstly, preparing a NaHTe solution; then, synthesizing CdTe quantum dots of which the surfaces are modified with thioglycollic acid, and adjusting the pH value to be 10-12 with KOH, so as to obtain the CdTe quantum dot fluorescent probe. According to the invention, carboxyl with negative charge on the surfaces of the CdTe quantum dots and target paraquat molecules with positive charge have the electrostatic interaction through the positive charge and negative charge, when the CdTe quantum dots and the paraquat approach to each other in space, the red spectrum band emitted by the CdTe quantum dot fluorescent probe can be absorbed by green target analyte paraquat modules through the fluorescence resonance energy transfer principle, and the detection of a trace amount of paraquat can be implemented through the utilization of the variation of the CdTe quantum dot fluorescence intensity.

Description

technical field [0001] The invention relates to the field of material science, in particular to a chemical preparation method of a CdTe quantum dot fluorescent probe capable of detecting trace amounts of paraquat. Background technique [0002] Pesticides play a huge role in the prevention and control of agricultural diseases, insects and weeds, and in ensuring high yields of crops. However, the uncontrolled use of pesticides poses a serious threat to my country's ecological environment and human health. In particular, pesticide residues in agricultural and animal husbandry products and food have chronic toxicity, "three causes" (carcinogenic, teratogenic, mutagenic) effects and environmental hormone effects on the human body. Incidents of poisoning directly caused by residues of highly toxic pesticides in agricultural products also occur from time to time. Pesticide residues pose a long-term serious threat to my country's food safety. In recent years, the public's sense of ...

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Problems solved by technology

At the same time, the method of labeling target analytes with organic fluorescent dyes has also been widely used, but traditional fluorescent dyes have insurmountable defects: the excitation spectrum is narrow; the emission spectrum of fluorescent dyes is very broad, and the fluorescence peak is within 100 nm. Sometimes there is a very long tail, which causes overlap between spectral peaks, which limits the number of fluorescent probes that can be applied at the same time; organic dyes are prone to photobleaching and photolysis, and photolysis products often have a killing effect on biomolecules; biomolecules and Each organic fluorescent dye attachment requires a specific method

At present, there are no related patents and literatures on the detection of pesticide residues by quantum dot fluorescent probes based on the principle of fluorescence resonance energy transfer

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