A tiny sensor that can detect pesticides on fruit in just a few minutes has been developed by researchers at Karolinska Institutet in Sweden. The technique uses flame-sprayed nanoparticles made from silver to increase the signal of chemicals.

“Reports show that up to half of all fruits sold in the EU contain pesticide residues that in larger quantities have been linked to human health problems,” said Georgios Sotiriou, the study’s corresponding author. [1]

Figure 1. Nano-sensors detect pesticides on fruit

Figure 1 shows the technology has been used in several research fields, including chemical and environmental analysis as well as to detect biomarkers for various diseases. However, high production costs and limited batch-to-batch reproducibility have so far hindered widespread application in food safety diagnostics. [2]

Flame spray technology

In the current study, the researchers created a SERS nano-sensor by using flame spray -- a well-established and cost-effective technique for depositing metallic coating -- to deliver small droplets of silver nanoparticles onto a glass surface. The researchers then finetuned the distance between the individual silver nanoparticles to enhance their sensitivity. To test their substance-detecting ability, they applied a thin layer of tracer dye on top of the sensors and used a spectrometer to uncover their molecular fingerprints. [3]

Detected pesticides on apples

To test the sensors’ practical application, the researchers calibrated them to detect low concentrations of parathion-ethyl, a toxic agricultural insecticide that is banned or restricted in most countries. A small amount of parathion-ethyl was placed on part of an apple. The residues were later collected with a cotton swab that was immersed in a solution to dissolve the pesticide molecules. The solution was dropped on the sensor, which confirmed the presence of pesticides

Next, the researchers want to explore if the nano-sensors can be applied to other areas such as discovering biomarkers for specific diseases at the point-of-care in resource-limited settings. [4]

References:

1. https://eandt.theiet.org/content/articles/2022/06/nano-sensors-detect-pesticides-on-fruit/
2. https://www.timesnownews.com/technology-science/researchers-develop-a-nano-sensor-to-detect-pesticides-on-fruits-article-92060532
3. https://www.sciencedaily.com/releases/2022/06/220607121014.htm
4. https://www.chemeurope.com/en/news/1176405/nano-sensor-detects-pesticides-on-fruit-in-minutes.html

Cite this article:

Thanusri swetha J (2022), Nano-sensors detect pesticides on fruit, Anatechmaz, pp. 75