Highly Luminescent Eu-Incorporated Zr-MOFs as Fluorescence Sensors for Detection of Hazardous Organic Compounds in Water and Fruit Samples.

Considering the risk of toxic organic compounds to both human health and the environment, highly luminescent Eu-incorporated amino-functionalized zirconium metal-organic frameworks, namely, Eu/MOF and Eu@MOF were synthesized via the solvothermal method. The synthesized luminescent europium-incorporated MOFs act as outstanding sensor materials for diphenylamine and dinitrobenzene detection in water and fruit samples. The synergistic effect of Eu metal ions and amino-functionalized MOFs enhances the luminescent properties of the MOFs improving the fluorescence sensing ability toward the analytes. The enhancement in the detection capacity of the Eu-incorporated sensors than the sole MOF toward toxic organic compounds was confirmed using the Stern-Volmer equation of limit of detection (LOD) measurements along with fluorescence lifetime measurements. The sensors exhibited turn-on fluorometric detection toward their respective analytes due to the inner filter effect. The plausible fluorescence sensing mechanism has been studied. The DFT calculations have been integrated to study the structure, stability, and charge transfer processes.