A new nano-sensor is able to recognize traces of pesticides present on fruit in just 5 minutes, thus avoiding the potential health problems that can arise from the consumption of these harmful substances.
The device, developed by researchers led by the Karolinska Institute in Stockholm, is cheap and easy to produce, making it suitable for common use in shops and supermarkets to monitor the quality of fruit sold to consumers.
The results of the study were published in the Advanced Science journal.
The researchers led by Haipeng Li used a powerful detection technique capable of increasing the signals coming from the biomolecules that they intend to search for by more than 1 million times: it is a technology already used in several research fields, but the high production costs and the limited reproducibility have so far hindered its application in the field of food safety.
The authors of the study, however, found a cheaper way to achieve the same result: they used heated silver nanoparticles and then sprayed onto a glass surface to create a metallic coating, then adjusting the distance between the individual nanoparticles to increase their size. sensitivity.
The researchers tested the sensor with Parathion, a highly toxic insecticide that was once used in agriculture and is now banned or very restricted in most countries.
The pesticide residues are removed from the fruit with a cotton swab, which is then immersed in a solution that releases the molecules of the harmful substance: finally dropping this solution on the sensor, the response is obtained within a few minutes.
"The technology will need to be validated by larger studies," Li says, "but we have provided first practical evidence of the applicability of these large-scale sensors for food safety."