Freshness of animal meat is an essential characteristic that determines its quality and safety. With advanced technology capable of preserving food for long periods of time, meat can be shipped around the world and eaten long after the animal has died. As the rate of global meat consumption increases, so does the demand for effective measures to age it.

Despite technological advances to keep meat as fresh as possible, some aging processes are inevitable. Adenosine triphosphate (ATP) is a molecule produced by respiration and is responsible for providing energy to cells. When an animal stops breathing, ATP synthesis also stops, and existing molecules break down into acids, first reducing taste and then safety. Hypoxanthine (HXA) and xanthine are intermediates in this transition. Their prevalence in meat indicates its freshness.

I AIP AdvancesFrom AIP Publishing, researchers from Vietnam Academy of Science and Technology, VNU University of Science, Hanoi University of Science and Technology, and Russian Academy of Sciences used graphene modified by zinc oxide nanoparticles to measure HXA. developed a biosensor using electrodes. The team demonstrated the sensor’s utility on pork.

Although many HXA sensing methods currently exist, they can be expensive and time-consuming and require expertise.

“Compared to modern methods of food testing, such as high-performance liquid chromatography, gas chromatography, mass spectrometry, atomic and molecular spectroscopy, and nuclear magnetic resonance spectroscopy, biosensors such as our sensors in terms of time, portability, high sens. offer superior benefits from .selectivity,” said author Ngo Thi Hong Lee.

The sensor is fabricated using a polyimide film, which is converted to porous graphene using a pulsed laser. The incorporated zinc oxide nanoparticles attract HXA molecules to the electrode surface. When HXA interacts with the electrode, it oxidizes and transfers its electrons, increasing the voltage of the electrode. The linear relationship between HXA and voltage increase enables easy determination of HXA content.

To assess the sensor’s capability, the researchers tested the solution with a known amount of HXA. After the impressive performance, the researchers measured the functionality of the biosensor using pork tenderloins purchased from a supermarket. The sensor performed with greater than 98% accuracy, reasonable detection limit, and low detection limit.

“In Vietnam, pork is the most consumed meat,” Li said. “Therefore, monitoring the quality of pork in the food industry in our country is an important requirement, that’s why we prioritized it.”

More than just pork, any meat product can be tested with this biosensor.