Method for visually and rapidly detecting malathion by using fluorescent/colorimetric bimodal sensor

Abstract

The invention belongs to the technical field of food safety detection, and particularly relates to a method for rapidly detecting malathion through fluorescence / colorimetric bimodal visualization. The method comprises the following steps: firstly, preparing a carbon quantum dot solution and a gold nanoparticle solution, mixing, adding an aptamer solution of malathion and a malathion standard solution, incubating, adding a sodium chloride solution, and incubating again to obtain a solution to be detected; measuring the fluorescence intensity of the to-be-detected solution at the fluorescence emission peak and the absorbance of the to-be-detected solution at the ultraviolet absorption peak under a certain excitation wavelength, simultaneously obtaining natural light optical pictures and fluorescence optical pictures of the to-be-detected solution, and sequentially arranging the pictures according to the malathion concentration from low to high to obtain a standard colorimetric card; respectively establishing prediction models according to the malathion concentration, the fluorescence intensity and the absorbance; the fluorescence intensity and absorbance of a to-be-detected sample are obtained and substituted into the corresponding prediction model, or a picture of the to-be-detected sample is collected and compared with a standard colorimetric card, so that rapid detection of malathion in the to-be-detected sample can be realized.

Description

technical field [0001] The invention belongs to the technical field of food safety detection, and in particular relates to a fluorescence / colorimetric dual-mode visual rapid detection method for malathion. Background technique [0002] Malathion, whose chemical name is O,O-dimethyl-S-[1,2-bis(ethoxycarbonyl)ethyl]phosphorodithioate, is a highly effective organophosphorus insecticide, It is mainly used to kill pests such as cabbage caterpillar, cabbage aphid and fruit tree stinkbug on wheat, beans, cotton, tea trees, fruit trees, vegetables and other crops, and plays an important role in improving the quality and output of agricultural products. At present, about 80,000 tons of malathion are used in my country every year. Malathion residues on agricultural products are absorbed by the human body, causing teratogenic, carcinogenic, mutagenic, endocrine disrupting, neurotoxic and other hazards to the human body. In view of the hazards of malathion, the establishment of detecti...

AI Technical Summary

Problems solved by technology

However, there are still deficiencies in the detection of malathion by existing sensors: on the one hand, the synthesis and modification of sensing materials are complicated, and the dosage is large and expensive; on the other hand, most nanosensors detect malathion only Modal detection, which only provides one output signal, is prone to false negative or false positive detection results, and compared with multi-modal sensors, the sensitivity and reliability of single-modal sensors are low; in addition, the use of sensors for malathion The detection of phosphorus still needs to be carried out in laboratories with good conditions, which cannot meet the needs of on-site rapid detection and visual detection

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