A fluorometric metal-organic framework oxygen sensor: from sensitive powder to portable optical fiber device

摘要

Nowadays, the development of high-sensitivity oxygen probes and portable detection devices are urgent required. Lanthanide metal-organic frameworks (MOFs), combining the advantages of lanthanide luminescent features and the inherent porosity of MOFs, show great potential for highly sensitive O-2 sensing. At the same time, optical fiber sensors have proven to be a simple and effective detection platform for portable and actual monitoring. In this work, we designed an O-2-sensitive porous lanthanide MOF by elaborately selecting organic ligand with the suitable high triplet-state level. The luminescent intensity of as-synthesized EuNDC (1,4-H2NDC = 1,4-naphthalenedicarboxylic acid) can be effectively quenched by O-2, giving rise to the most outstanding detection performance than other reported lanthanide MOFs with high sensitivity (93.5% quenched at 1 bar O-2, I-0/I-100 = 15.4, K-sv = 13.3 bar(-1), LOD = 0.21 mbar), good reversibility, and short response/recovery times (10/70 s). After that, we proposed and developed a reflection type optical fiber sensor by integrating EuNDC and silica fiber in PDMS film for remote, in-field and real-time O-2 monitoring.