posted on 2023-12-14, 21:04authored byMohamed
H. Hassan, Silvana Andreescu
Metal–organic frameworks (MOFs)
with intrinsic luminescent
properties, modular structure, and tunable electronic properties,
provide unique opportunities for designing target-specific molecular
sensors by systematically choosing their constituent building blocks.
We report a simple one-step MOF-based sensing platform for phosphate
(P) detection that combines the luminescent properties of 2-aminoterephthalic
acid (ATA) with the affinity of rationally selected nodes in UiO-66-NH2 to bind with P. This MOF possesses an electron-donating amine
group that controls the light-harvesting characteristics of the linkers.
Substituting Zr6 node with Ce6 or Hf6 results in a series of isostructural MOFs with distinct optical
properties that are nonexistent in the unsubstituted MOF. We have
utilized these MOFs to quantitatively measure P, using its ability
to bind strongly to metal nodes inhibiting the LMCT process and altering
the linker’s photon emission. Using this system, detection
limits of 4.5, 7.2 and 10.5 μM were obtained for the UiO-66-NH2(Ce), UiO-66-NH2, and UiO-66-NH2(Hf)
respectively, adopting a straightforward single step procedure. These
results demonstrate that the selection of metal nodes in a series
of isostructural MOFs can be used to modulate their electronic properties
and create sensing probes possessing the desired characteristics needed
for the detection of environmental contaminants.