Sensor detects the presence of pesticides in food

May 05, 2023 |

Finding out whether a food sample contains traces of pesticides via traditional methods requires grinding up the sample and subjecting it to time-consuming chemical processes. This led researchers from the University of University of São Paulo (USP) to create a kraft paper-based electrochemical sensor that detects pesticides in food in a quicker and cheaper way.

The device is highly sensitive and resembles the mechanism in glucometers. Linked to an electronic device, the sensor works in real time and can determine the presence of carbendazim, a banned fungicide claimed to be still in use in Brazil, on apples and cabbages.

Using the silkscreen process, the device consists of a paper substrate modified with carbon ink that undergoes electrochemical treatment in an acid medium, activating the carboxyl groups which makes the detection possible. Once it comes into contact with a sample contaminated with carbendazim, an electrochemical oxidation reaction occurs. Quantities of carbendazim are measured via electric current.

The team evaluated the stability and structure of the paper substrate and they found out that both types of paper, kraft paper and parchment, are stable enough to be used as a substrate for the tool. Further observations indicated that the porousness of the kraft paper allowed for more sensitivity while paper-based electrodes could be used in various other applications.

Thiago Serafim Martins, a postdoctoral fellow at IFSC-USP, stated that the successful development of electrochemical sensors based on paper makes for a more malleable material compared to the commercial electrodes that are made of either plastic or ceramic material.

The sensor is wearable and is amenable for continuous monitoring of pesticides in both agriculture and food industry, eliminating the need for complex food scanning processes. Inspection gets easier, cheaper and reliable for supermarkets, restaurants, and importers alike.