Abstracts

Metal–organic frameworks (MOFs), also known as porous coordination polymers, are innovative functional materials characterized by a wide variety of framework architectures. Among them, nanoMOFs have emerged as nanomaterials with nanosized pores that can be significantly modified due to confinement and chain extension, improving physical and chemical properties when compared with bulk materials. For analytical chemistry, the synthesis of nanoMOFs with controllable pore size, structure and luminescent properties has driven to the development of novelty sensing platforms. The specific pore size and host-guest interaction ensure the selectivity of the designed sensor to detect small molecules or metals [1]. These excellent properties, the possibility to be used in membranes technology and their low toxicity are the main driven forces towards the development of nano-MOFs based food sensors. In this regard, food safety is one of the most concerning issues at this time. Food degradation during storage and commercialization in terms of microbiological and physicochemical properties is quite variable, it depends of the conservation procedure and type of food. Some compounds, that can be used as degradation markers, are biogenic amines (BAs). BAs appear because of the metabolic activities of microorganisms in food and they can be present in all types of foods with high protein or free amino acid content, such as fish, meat or wines [2].As stated before, the combination of nanoMOFs properties and and amines as food safety markers could be an alternative in the development of non-invasive sensors to be implemented in smart packaging. In this work, we have designed and tested a luminiscent based Cu-nanoMOF to detect and quantify Biogenic Amines (BAs) in food. This alternative will be evaluated as a food safety strategy to be included in smart packages. This proposal try to develop a luminescent nano-MOF to detect volatile BAs. For this purpose, the changes in luminescence properties of the fluorescent copper MOF (CuDOBCD) when exposed to different amines, including cadaverine and putrescine, have been studied. The optical behaviour of the nano MOFs varies depending on the amine, and a fluorescence quenching is observed at different reaction times, making possible the design of a "turn off" and non-invasive fluorescence sensor. PVC and Cu nano-MOF membranes were designed and after exposing these nanoMOF membranes to different BAs colourimetric changes (from green to brown) and fluorescence quenching were observed. After chemical development a portable and miniaturized device has been tested to confirm food safety status in field.References[1] Liu Y., et al.., Strategies to fabricate metal–organic framework (MOF)-based luminescent sensing platforms, Journal of Materials Chemistry C, 2019, 7(35),10743-10763. http://dx.doi.org/10.1039/C9TC03208[2] Wunderlichová, L. et al. Formation, degradation, and detoxification of putrescine by foodborne bacteria: a review. Comprehensive Reviews in Food Science and Food Safety, 2014,13(5), 1012-1030. https://doi.org/10.1111/1541-4337.12099