In this work, metal–organic framework (MOF) UMCM-1 and amino functionalized MOF (i.e., UMCM-1-NH₂) were synthesized and their performances as luminescent probes were investigated. It is found that both unmodified and amino functionalized MOFs exhibit a luminescence quenching effect on metal ions. In particular, the amino functionalized MOF (UMCM-1-NH₂) possesses high sensitivity and selectivity for Fe³⁺ ions and the luminescence is completely quenched in 10⁻³ M DMF solution of Fe³⁺. Moreover, the regenerated UMCM-1-NH₂ still has high selectivity for Fe³⁺ ions, which suggests that the functionalized UMCM-1-NH₂ is a promising luminescent probe for selectively sensing iron ions.