An Eu-based MOF as fluorescent probe for the sensitive detection of L-tryptophan

A new type of 3D MOF, namely [Eu(L)2NO3]n(HL ​= ​3,5-bis(triazol-1-yl)-benzoic acid), has been designed and synthesized. The unique crystal structure is derived from the combination of the ligand containing triazole moiety and lanthanide Eu(Ⅲ) ion. The application of the ratio of dual-signal improves the accuracy for detecting amino acids. The limit of detection for L-tryptophan in the range of 0–633 ​μM is 0.00424 ​μM, reaching a μM level. And the recycling experiment proves that the Eu-MOF can be used multiple times. This research provides great significance for using metal-organic framework (MOF) as the platform for fluorescent sensing.