A novel europium-centered metal–organic
framework fabricated
from a symmetric and rigid ligand with tetracarboxylate groups, 2,6-di(2′,5′-dicarboxylphenyl)pyridine
(H4ddpp), has been synthesized solvothermally. Characterized
by single-crystal X-ray diffraction, compound 1 features
a 3D microporous structure with a butterfly-shaped trinuclear Eu3(COO)6 secondary building unit. Interestingly,
three kinds of 1D open channels viewed in different directions in
compound 1 are discovered, and the void ratio is calculated
to be 47.5% by PLATON software. Solid-state luminescent experiments
at 298 K reveal that compound 1 displays naked-eye characteristic
red emission of Eu3+ ions monitoring the typical 5D0 → 7F2 transition. The
exploration of luminescent sensing tests discloses that compound 1 has an outstanding capacity for recognizing urinary 1-hydroxypyrene
(1-HP) with a quite fast response and high sensitivity, giving the
quenching efficiency of 98.2% after the immersion time for just 1
min and 73.2% with the amount of 1-HP only 0.05 mg/mL. To our knowledge,
it is the first reported Eu-MOF as an extremely fast-responsive and
highly sensitive luminescent sensor for 1-HP which is interference-free
from other urinary components. Furthermore, the successful preparation
of the luminescent test papers makes compound 1 convenient,
easy, and real-time in the application for sensing 1-HP in biomedical
and biological fields.