Incorporating copper nanoclusters into a zeolitic imidazole framework-90 for use as a highly sensitive adenosine triphosphate sensing system to evaluate the freshness of aquatic products

Abstract Based on the encapsulation of copper nanoclusters (CuNCs) mixed with Al3+ into a zeolitic imidazole framework-90 (ZIF-90) to form CuNCs-Al3+/ZIF-90 composites, a novel, simple and sensitive fluorescent sensor was developed to detect adenosine triphosphate (ATP) and then evaluate the freshness of aquatic products by determining the changes in the level of ATP. Encapsulated CuNCs could be released from the ZIF-90 after their addition to ATP, resulting in the fluorescence quenching of this system. Based on this phenomenon, the sensitive detection of ATP was realized with a detection limit of 0.67 μM, and a good linear relationship was observed between the fluorescence quenching ratios of the CuNCs-Al3+/ZIF-90 composites and ATP in the concentration range from 1 to 2000 μM. Moreover, satisfactory results were obtained when the proposed ATP detection method was applied to real samples to evaluate the freshness of aquatic products.