Two seconds to test the fruit and vegetable "pesticide residue"!My scientist develops a new portable sensor platform

I am afraid of pesticide residues when buying vegetables, and eating fruits is also afraid of pesticide residues ... People often "talk about pesticide color changes."

Recently, Jiang Changlong, a researcher at the Institute of Solid Physics, Institute of Solid Physics of the Institute of Hefei Material Sciences of the Chinese Academy of Sciences, has developed a new type of portable sensing platform (hereinafter referred to as a sensing platform). Residual, the final concentration result is directly displayed on the smartphone. Related research results were published in the Materials Materials Magazine.

"See" results for 2 seconds on the scene

Δ Research Group members use test strips to detect straw glyphosate research groups.

"People only need to wet the surface of the fruits and vegetables, and wipe it gently on the surface with the test paper. After about 2 seconds, they will be illuminated by ultraviolet lights. The color of the glyphosate residue can be judged by the color change of the test strip." Jiang Changlong Jiang Changlong. Introduce to reporters.

If the test strip is blue, it means that the concentration of the glyphosate residue is very low; when the test strip is pink, it means that the concentration is large; when the test strip presents orange -red, it means that the concentration is high.

"This method belongs to the first screen, which is suitable for people to self -test at home." Jiang Changlong said that if you want to get more accurate results, you need to put the test strip into the test strip of the sensing platform. The ultraviolet lights comes with the sensing platform are irradiated, and then the test strip photos are taken with a mobile phone. The color recognition software of the mobile phone is automatically analyzed and transformed, showing that the final result of the concentration of the agricultural residue exceeds the standard or it has not exceeded the standard.

Jiang Changlong introduced that the sensor includes sensors, smartphones that can read data, and mobile phone accessories that provide fluorescent detection environment. "The sensor is the main" hero ". It is composed of the blue carbon dots and gold nano groups designed by the team.

The principle is to react with the carbon point when the glyphosate is added to the sensor, causing the blue fluorescent of the carbon dot to quickly lying, and the orange fluorescence of the golden nanoplasting cluster remains unchanged. From a visual point of view, the fluorescent color changes in the test strip change from blue to pink to orange -red.

The team tested some actual samples, such as the fruits and vegetables and water samples with the residues of glyphosate. The test results were basically the same as the test results in the laboratory.

Jiang Changlong said that the sensors developed by the team are more fast and convenient. Those who have not been trained can also operate and use it, and realize the on -site or real -time detection of laboratory testing. Individual consumers.

"Pesticide residue" does not mean that "pesticide residues exceed the standard"

Δ ratio fluorescent sensor quickly visualized quantitative detection of glyphosate residual schematic diagram Research group.

Greening is currently the largest internationally used herbicide, occupying an important position in organic phosphorus pesticides. "This is also an important reason why the team chooses glyphosate for the test of agricultural disability." Jiang Changlong said.

After the glyphosate is absorbed by the stems and leaves, it is transmitted to all parts of the plant to inhibit the alcohol pritarinylcelactinogenase in the plant, thereby inhibiting the transformation of the reckless grassin to phenylalanine, tyrosine, and drenate. The protein synthesis is disturbed, causing plants to die.

However, higher usage and unreasonable methods of use will cause the residue of glyphosate in agricultural products to exceed the standard.

With the improvement of living standards, people's awareness and safety awareness of environmental protection have increased day by day. Jiang Changlong said, "At present, people usually use laboratory instruments or enzyme suppression methods to detect agricultural residues. However, this test is mostly completed by professionals. The detection instruments are expensive and the test results can only come out for two to three days."

Therefore, the method of developing rapid and effective, on -site detection of glyphosate residues has become a key link for controlling and handling organic phosphorus farmers' pollution and harm.

"It should be pointed out that pesticide residues are not the same as that of pesticide residues exceeding the standard. According to the residual limit of agricultural residues, the maximum limit of glyphosate residues in China is 4.14 microol." Jiang Changlong said that if pesticide residues do not exceed the maximum limit, it is safe to be safe People can eat with confidence.

In addition, it is worth noting that as agricultural products such as fruits and vegetables account for increasingly the proportion of diets in our country, its quality and safety has attracted much attention, and the residual limited standards are also modifying in the direction of "science and rigor".

Build a variety of target analysis fast detection platforms

Δ Monitoring platform based on smartphones can visualize and quantitative detection of glyphosate research group charts.

"This article reports a fast visual fluorescent sensor platform for quantitative detection of glyphosate. The innovation of this method is to deal with fluorescent signals in combination with smartphones, which is convenient and accurate. Fluorescent substances as signals, not dependent on enzymes, have certain application potential in on -site detection, "said a reviewer.

However, Jiang Changlong admits that the sensors developed this time are only targeted at glyphosate residues. "At present, the team is exploring and developing other pesticides' fast inspection methods and devices, such as chrysanthemums, amino methyl acid."

In addition, the detection signal of the sensor depends on the changes in the fluorescent color of wide light spectrum, and this fluorescent color may be affected by the use of environmental light.

Jiang Changlong said, "We hope to further upgrade the accessories of the detection platform, or develop other detection methods and build sensors to avoid bad interference of all external factors for detection results."

In the next step, the research team will focus on exploring the preparation of multi -color glowing nano probes, further build a fast detection platform for multiple target analysis objects, and establish an evaluation system based on nano -optical effect sensors to be used in the environment of various pollutants in the environment. With technical standards, new progress is expected to make visual analysis and testing of human health warning.

Source: Journal of Science

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