Serological tests could open up new paths of innovation also for food safety control. The Sensing Technologies Lab of the Free University of Bozen-Bolzano (in South Tyrol, Italy) has developed an effective, precise and economical tool to prevent food poisoning: immunosensors whose electrodes, coated with antibodies, allow a simple control of histamine contamination in foods containing proteins, such as fish. A paper on this project was recently published by the international scientific journal Biosensors.
Nowadays we can find them everywhere: in smartphones and cars, in production plants or in building management. Sensors have become an integral part of our daily lives, both private and professional. The researchers a the Sensing Technologies Lab at the Faculty of Science and Technology test the latest technologies to explore new fields of application in the measurement of a wide range of physical and chemical properties. The laboratory’s research team – consisting of physicists, engineers, chemists, biotechnologists and food science and technology experts – specializes primarily in research on printed sensors that can be produced economically and flexibly using special conductive inks.
One of the current projects has made the cover of the latest issue of the international magazine Biosensors. Flexible and Printed Electrochemical Immunosensor Coated with Oxygen Plasma Treated SWCNTs for Histamine Detection: this is the title of the paper published by the chemical engineer Shkodra Bajramshahe. The article presents the important preliminary results, achieved during her PhD thesis at the Faculty of Science and Technology. The Kosovo-born scientist obtained a degree in Chemistry and Chemical Engineering in Pristina with the highest marks and then conducted research at the University of Umeå in Sweden, where she worked on her master’s thesis in the field of chromatography, a method of chemical analysis that permits the identification and separation of ingredients contained in mixtures of various substances. In November 2018, Bajramshahe was accepted to the international doctoral program in Food Engineering and Biotechnology and works at the Free University of Bozen/Bolzano, in the Sensing Technologies Lab.
Together with the multidisciplinary team of the laboratory, Bajramshahe has succeeded in developing an immunosensor that will make the testing of histamine contamination – the molecule responsible for food poisoning from fish products – in the simplest and most cost-effective way possible. “Histamines are mainly found in high protein foods such as fish and, at high concentrations, can cause food poisoning”, says Bajramshahe. A well-known example is scombroid syndrome, an intoxication that can occur when one eats fish that is not fresh or canned fish with a dangerously high concentration of histamine. “The goal of our project is to develop a method that can be used to quickly and easily detect excessive histamine content without the need of laboratory testing”, says the researcher. Most of the tests to-date are based on laboratory tests that include the use of environmentally harmful chemicals.
The Sensing Technologies Lab approach, on the other hand, uses sensors printed with silver ink or silver chloride and coated with histamine antibodies. The reaction between these antibodies and histamine is then converted into an electrochemical signal.
“To increase the strength of the electrochemical signal, we sprayed the electrodes with a solution of carbon nanotubes”, explains the researcher. The latter were activated with oxygen plasma to minimize their water-repellent effect. The research has not yet produced sensors ready for the market but the scientific community has appreciated the discovery. “In order to actually use the sensors in food processing plants, a portable system that translates the signals into concrete histamine values is also necessary”, adds Bajramshahe. Once this has been developed, the industry will have a low-cost instrument that can be used by non-specialist personnel to make quality measurements directly on the food product.
“This promising project is a symbol of the work in our laboratory”, says Prof. Paolo Lugli, head of Sensing Technologies Lab and Rector of the Free University of Bozen-Bolzano. In other research projects, his multidisciplinary team is also working on innovative sensor-based technologies to do research in food, environmental and agricultural laboratories faster and more cheaply.
“Our aim is to increase the competitiveness of local companies by developing new technologies and, especially in the food industry, to contribute to greater food safety and compliance with quality standards”, Lugli points out.