Fast Response and High Sensitivity Europium Metal Organic Framework Fluorescent Probe with Chelating Terpyridine Sites for Fe3+

Iron is one of the most important elements in the metabolic process for all living system. However, both its deficiency and excess from normal permissible limits can induce serious disorders. We synthesized a europium-based metal-organic framework (Eu-MOF), EuL3 (L = 4'-(4-carboxyphenyl)-2,2': 6',2 ''-terpyridine), under hydrothermal conditions, and used it as a solid luminescence sensor for Fe3+ ions. The robust EuL3 shows fast response (similar to 1 min) and high sensitivity (Stern-Volmer constant K-SV = 4.1 x 10(3) L/mol) for Fe3+ ions in aqueous solution or biological systems due to the existence of chelating terpyridine and open channels. The simple and portable test paper based on the EuL3 fluorescent sensor system provides a convenient and reliable detection of Fe3+ in every day applications. This pioneering work contributes to extend the potential application of Ln-MOFs to the biological and environmental areas.