A device developed at the University of São Paulo is similar to the glucometers used by diabetics to measure blood sugar levels: it detects and quantifies trace amounts of carbendazim when it comes in contact with the surface of fruits and vegetables.
Researchers at the University of Sao Paulo (USP) in Brazil have developed a kraft paper-based electrochemical sensor that can detect trace levels of pesticides in fruits and vegetables in real time when connected to an electronic device. For example, carbendazim, a banned but widely used fungicide in Brazil, can be detected in apples and cabbage.
The research behind this invention is the result of three projects (18/22214-6, 19/13514-9, and 22/03758-0) and the San Carlos Institute of Physics (IFSC-USP) and the San Carlos Institute of Chemistry was supported by FAPESP through its affiliated groups. (IQSC-USP). The results are reported in an article published in the journal Food Chemistry.
“Traditional methods to determine whether food samples contain trace amounts of pesticides require the samples to be pulverized and subjected to time-consuming chemical processes before such substances can be detected. Wearable sensors, like the one we developed to continuously monitor pesticides in the food industry, will eliminate the need for these complex processes, making inspection much easier and simpler for supermarkets, restaurants, or importers, for example. , inexpensive, and reliable.
The new device is more sensitive and resembles a glucometer used by diabetics to measure blood sugar, except the pesticide food scan results are displayed on your smartphone. “In our tests, its sensitivity was similar to that of conventional methods. It’s also fast and inexpensive,” said José Luiz Bott Neto, the corresponding author of the article and a postdoctoral fellow at IFSC-USP. says.
Usage
The device basically consists of a paper substrate modified with carbon ink and subjected to an electrochemical treatment in an acidic medium to activate the carboxyl groups, enabling detection, explained Bott Neto.
“We use a silk-screen process to transfer carbon conductive ink onto strips of kraft paper, thereby creating a device based on electrochemistry. There are three carbon electrodes, which activate carboxyl groups. It is immersed in an acidic solution for the carbon electrode structure, i.e. oxygen atoms are attached to the structure of the carbon electrode.When in contact with a sample contaminated with carbendazim, the sensor undergoes an electrochemical oxidation reaction that allows the detection of the disinfectant. The amount of carbendazim is measured via an electric current,” he said.
In developing the device, researchers evaluated the stability and structure of the paper substrate. “The characterization of the paper itself was an important part of our research.
best option
Researchers analyzed kraft paper and parchment and found that both types of paper are stable enough to serve as substrates for sensors. However, the porosity of kraft paper increases the sensitivity of the sensor and forms carboxyl groups that form during electrochemical activation, Martins explained, making paper-based electrodes useful in many applications. “There are commercially available electrodes made of plastic or ceramic materials. We have successfully developed a paper-based electrochemical sensor. It could be useful in many areas, not only in supermarkets, but also in healthcare.”
Original: Paper-based sensor for fast and inexpensive detection of pesticides in food
Than: University of Sao Paulo
