Tetraphenylpyrazine-Based Luminescent Metal–Organic Framework for Chemical Sensing of Carcinoids Biomarkers

A new non-interpenetrated three-dimensional
(3D) pillared-layered
TPP-based LMOF [Zn3(TPyTPP)0.5(BDC)3]·8DMF (denoted as Zn-MOF 1) was successfully prepared (TPyTPP
= tetrakis­(4-(pyridin-4-yl)­phenyl)­pyrazine and H2BDC =
1,4-benzenedicarboxylic acid). Zn-MOF 1 was characterized by single-crystal
X-ray diffraction, PXRD, IR, N2 adsorption, thermogravimetric
analysis, and luminescent spectrum. Impressively, luminescent sensing
studies reveal that activated Zn-MOF 1 not only displays excellent
luminescence-quenching efficiency with the values of high Ksv and low LODs toward 5-hydroxytryptamine (5-HT)
and 5-hydroxyindole-3-acetic acid (5-HIAA), respectively, but also
possesses outstanding sensing characteristics in terms of fast response,
high sensitivity, and specific selectivity. Zn-MOF 1 performs as efficient
sensing of carcinoid biomarkers to provide a fresh detection platform
for the diagnosis of carcinoids. In addition, the sensing mechanism
was also explored on the basis of ultraviolet–visible (UV–vis)
absorption, DFT calculations, and structural analysis.