Controllable synthesis of Tb-based metal–organic frameworks as an efficient fluorescent sensor for Cu²⁺ detection

A series of Tb-based metal–organic frameworks (Tb-MOFs) were successfully synthesized by a solvothermal method. The size and morphology of the as-obtained Tb-MOFs can be effectively controlled via regulating the experimental conditions such as the volume fraction of DMF and the molar ratio of Tb³⁺ to NaOH. It is found that all the samples exhibit strong green emissions under ultraviolet excitation, corresponding to ⁵D₄ → ⁷F_J transitions of Tb³⁺. Interestingly, Tb-MOFs displayed an efficient and distinct luminescence quenching by Cu²⁺ in aqueous solutions. The competitive fluorescence detection experiments indicate that these Tb-MOFs sensors can be used as a high selective and sensitive sensor of Cu²⁺ detection with the detection limit of 10 µmol·L⁻¹, which can be used as a promising fluorescence sensor for Cu²⁺ detection in daily life.