Meat and fish freshness evaluation by functionalized cantilever-based biosensors

Meat spoilage is a result of an increase in the number of microorganisms and increased levels of biogenic amines (e.g. cadaverine). Destruction of non-spoiled meat products results in substantial waste of resources each year. Currently, the expiration date of meat-products is determined by either subjective sensory and/or expensive and time-consuming microbiological analysis. Cadaverine levels have been demonstrated to be related to the product freshness; however current sensing methods require bulky and expensive chromatography techniques. In this work, the cadaverine binding to a functionalization layer of cyclam (1,4,8,11-tetraazacyclotetradecane) is demonstrated by a systematic study of cyclam/solvent solution influence on morphology and binding. The degradation of the functionalization layer due to storage conditions has also been investigated, and the optimum solvent for the functionalization solution is found to be ethoxyethanol. Functionalized surfaces and cantilevers have been exposed to different types of meat (beef, fish, chicken or pork) and the cadaverine binding has been demonstrated, either by morphology changes (surfaces) or by changes on cantilever resonance frequency due to mass increase (cantilever). The results show a higher cadaverine emission rate for fish, followed by chicken, beef and finally pork.