Cryogenic Nanothermometer Based on the MIL-103(Tb,Eu) Metal-Organic Framework

The microporous metal-organic framework MIL-103 doped with Tb3+ and Eu3+, formulated as [(Tb0.95Eu0.05)(btb)(H2O)](solv)(x) [H(3)btb = 1,3,5-tris(4-carboxyphenyl)benzene; solv = H2O, CH3OH] has been shown to be a good platform for luminescent ratiometric thermometry. Although operative over a wide range of temperatures (10-320 K), this material exhibits, in the cryogenic range (<100 K), one of the best performances of metal-organic frameworks, with a relative thermal sensitivity of 2.85%K-1 at 14 K. The material exists in the form of nanoparticles, suitable for nanothermometry applications (e.g., microfluidics). Moreover, as MIL-103 is nanoporous, its use as a multisensing platform deserves further consideration in the near future.