Sensor identifies sodium nitrite in drinks utilizing laser-modified cork

A crew of researchers from the Federal College of São Carlos (UFSCar) within the state of São Paulo, Brazil, has developed a sensor that may determine sodium nitrite (NaNO₂) in varied drinks, together with mineral water, orange juice, and wine. This inorganic salt is used as a preservative and fixative to offer merchandise resembling ham, bacon, and sausages their pink or crimson coloration. Relying on the quantity, it could actually trigger critical well being issues by resulting in the formation of nitrosamines, that are carcinogenic compounds.

“This threat motivated us to develop a easy, quick, and accessible method to detect the compound and make sure the high quality and security of liquid consumption,” says Bruno Campos Janegitz, head of the Laboratory of Sensors, Nanomedicine, and Nanostructured Supplies (LSNano) at UFSCar. Janegitz coordinated the research, which was printed within the journal Microchimica Acta.

“Detection [of NaNO₂] in drinks, particularly wines, is necessary for high quality management, since its use just isn’t legally permitted in Brazil and most international locations,” the authors write within the article.

In response to the researcher, LSNano initiatives purpose to make use of supplies from low-cost platforms that generate added worth whereas respecting the atmosphere. On this case, cork was chosen as the start line as a result of it’s light-weight, pure, and cheap.

The samples had been laser-marked to rework them into graphene, a extremely conductive type of carbon, as if concentrated mild had drawn paths within the cork. “This course of is sustainable, would not require poisonous reagents, and leads to a extremely conductive materials, which is crucial as a result of nitrite undergoes well-known electrochemical oxidation. Subsequently, we want a extremely conductive sensor to detect the compound,” Janegitz explains.

Subsequent, a water-proof spray was utilized to the cork to forestall any liquid from seeping into the fabric and compromising the sensor’s response. Then, a layer of nail polish was utilized to delimit the modified space. The samples had been then positioned in an oven at 40 °C for half-hour to dry and optimize the laser parameters.

The subsequent step within the undertaking was to position samples of water, orange juice, and wine diluted in an electrolyte answer with salts simulating nitrite on the graphene.

The outcomes confirmed that the sensor carried out excellently, with excessive sensitivity and good stability. It was capable of detect nitrite at concentrations appropriate with these related to meals and environmental security.

The undertaking remains to be within the laboratory validation part, and enhancements to the design are wanted for sensible use.