Ratiometric fluorescence temperature sensing based on thermal coupling energy levels of a single-lanthanide dysprosium MOF

The luminescence intensity ratio generated by thermally coupled energy levels (TCELs) based on lanthanide ions has been demonstrated to be a reliable technique for optical thermometry. In this study, we developed a new single-lanthanide (S’LnMOF), DyBPDA, by a straightforward solvothermal method with the [1,1′-biphenyl]-3,5-dicarboxylic acid (H2BPDA) as a linker and Dy3+ as a single luminescence center. Based on the dual emission originating from TCELs of Dy3+ (4I15/2 and 4F9/2 → 6H15/2), DyBPDA enables as a ratiometric temperature sensor in the range 303–443 K with a maximum relative sensitivity of 0.41%·K−1. This work provides a reference for the facile preparation of S'LnMOF, which further contributes to the optical temperature sensing technology based on TCELs.