Novel sensor developed for rapid detection of harmful insecticides

Recently, a research team led by Prof. JIANG Changlong from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has constructed a visual sensing platform based on DNA aptamer-based sensing system. This sensor can be used for rapid and quantitative detection of organophosphate insecticides, such as profenofos and isocarbophos, in the environment and food.

The research findings have been published in Analytical Chemistry.

Organophosphate insecticides, like profenofos and isocarbophos, are widely used for their effectiveness in controlling agricultural pests. However, excessive use can leave harmful residues, posing serious health risks. Developing accurate, efficient methods for detecting these residues is crucial for environmental and food safety. Current large-scale detection instruments are inadequate for on-site, rapid, and quantitative analysis. Therefore, creating a rapid, sensitive, and selective method for detecting organophosphate residues is vital for protecting human health.

In this research, researchers developed a new sensor that uses color changes to detect organophosphate insecticides like profenofos and isocarbophos. This sensor works because of a special interaction between the insecticides and designed DNA strands called aptamers.

The sensor includes a green dye (SG-I) that fits into a G-quadruplex structure in the aptamer, making the sensor glow green. When organophosphate insecticides are present, they bind tightly to the aptamers, disrupting this green glow. This binding causes the green fluorescence to fade and enhances the blue fluorescence from the G-quadruplex, changing the color from green to blue. This color change allows for the visual detection of these insecticides, with very low detection limits of 2.48 nM for profenofos and 3.01 nM for isocarbophos.

In addition, researchers have combined 3D printing technology and color-identifier application on smartphone to develop a portable detection platform.

"It can rapidly and visually quantify the organophosphate insecticides, providing a new strategy for on-site rapid detection of pesticide residues," said Prof. JIANG.

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