Meat biosensor to determine freshness

Despite the technological advances keeping meat fresh for as long as possible, certain aging processes are unavoidable. Adenosine triphosphate (ATP) is a molecule produced by breathing and responsible for providing energy to cells. When an animal stops breathing, ATP synthesis also stops, and the existing molecules decompose into acid, diminishing first flavour and then safety. Hypoxanthine (HXA) and xanthine are intermediate steps in this transition. Therefore, assessing the prevalence of HXA in meat is a good indicator of food freshness.

While many HXA sensing methods currently exist in the food industry, they can be costly and time-consuming and require specialists.

Researchers from the Vietnam Academy of Science and Technology, VNU University of Science, Hanoi University of Science and Technology, and the Russian Academy of Sciences have now developed a biosensor using graphene electrodes modified by zinc oxide nanoparticles to measure HXA.

In comparison to modern food-testing methods, like high-performance liquid chromatography, gas chromatography, mass spectrometry, atomic and molecular spectroscopy and nuclear magnetic resonance spectroscopy, the biosensor has been designed to offer advantages in time, portability, high sensitivity and selectivity.

The sensor is produced using a polyimide film, which is converted into porous graphene using a pulsed laser. The added zinc oxide nanoparticles attract the HXA molecules to the electrode surface. When HXA interacts with the electrode, it oxidises and transfers its electrons, spiking the electrode’s voltage. The linear relationship between HXA and voltage increase enables easy determination of HXA content.

To assess the sensor’s ability, the researchers tested solutions with known quantities of HXA and achieved good results. They then measured the biosensor’s practicality using pork tenderloins purchased from a supermarket. The sensor performed with over 98% accuracy, favourable detection range and low detection limit.

The sensor is designed to be suitable for not just pork meat — it can be used evaluate any type of meat.

The research findings have been published In AIP Advances.

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