Highly sensitive and selective fluorescent probe for Ag + based on a Eu 3+ post-functionalized metal–organic framework in aqueous media

A new class of lanthanide luminescent MOFs was generated by postsynthetic modification encapsulating Eu ³⁺ into the pores of MIL-121 (Eu ³⁺ @MIL-121). More significantly, the robust Eu ³⁺ @MIL-121 shows fast response and high sensitivity to Ag ⁺ ions in aqueous solution, due to a great enhancement in the Eu-luminescence.