The recent discovery of lanthanide organic frameworks (Ln-MOFs) offers the potential for biomarkers or metabolites sensing: This is another field that is closely connected with life science and medicine. In this work, a stable and luminescent phosphonate Ln-MOFs MIL-91(Al:Eu) and its derivatives composite Cu2+@MIL-91(Al:Eu) were synthesized. The rebound of luminescence of Cu2+@MIL-91(Al:Eu) that origin of Eu3 is observed in the presence of uric acid. This On-Off-On pattern is utilized for detecting uric acid, which is the final metabolite of purine. The composite reveals excellent selectivity and sensitivity for sensing uric acid. The detection of uric acid in real urine is also investigated. The effective detection of uric acid and tentative diagnosis of hyperuricuria on the basis of test paper is demonstrate.