Multifunctional Luminescent Eu(III)-Based Metal–Organic Framework for Sensing Methanol and Detection and Adsorption of Fe(III) Ions in Aqueous Solution

Abstract

A novel lanthanide-organic framework (Eu-HODA), consisting of 2,2',3,3'-oxidiphthalic acids as efficient sensitizing units, is assembled and characterized. Eu-HODA features rare chiral helical channels despite the achiral nature of HODA. It is found that this MOF shows a unique luminescent response to methanol, in contrast to n-propanol and ethanol. Eu-HODA reveals a turn-off luminescence switching initiated by acetone molecules with an EC of 0.03 vol %, which is below the occupational exposure limit of acetone stipulated by the American Conference of Governmental Industrial Hygienists. Furthermore, it also exhibits high sensitivity (Stern-Volmer constant K = 2.09 × 10 L/mol) and low detection limit (6.4 ppb) for Fe ions in pure water because of the existence of uncoordinated carboxyl groups within open frameworks. Eu-HODA-based test paper provides a simple and reliable detection method for Fe in practical applications.

A Highly Sensitive and Recyclable Ln‐MOF Luminescent Sensor for the Efficient Detection of Fe3+ and CrVI Anions

“…Then, Fe 3+ will interact with the undeprotonated carboxylic acids and N atoms of carbazoles in the channel, quenching the luminescence. Therefore, we guess that the luminescence quenching detection of Fe 3+ cations based on 1 and 2 may be attributed to the weak Fe 3+ ‐O/Fe 3+ ‐N interactions . Certainly, the above XPS has proved our thought.…”

Enhancing the Fe3+ Sensing Sensitivity by Energy Transfer and Phase Transformation in a Bimetallic Lanthanide Metal‐Organic Framework

“…The K SV value increases by 36.6% from EuMOF‐ 1 to Eu 0.6 Tb 0.4 , which possesses the maximum of 6517.23 M −1 . The largest K SV quenching constant towards Fe 3+ herein is bigger than those in early EuMOFs with terpyridyl and urea groups anchored in their one‐dimensional and three dimensional structures, although it does not reach the highest level of some other reported Eu‐based MOFs (Table S4) ,,,. Thus, the results of our present study would provide a novel strategy to increase K SV and enhance quenching effect and sensitivity by the synergistic effect of structure transformation and energy transfer.…”

Multishelled Hollow Structures of Yttrium Oxide for the Highly Selective and Ultrasensitive Detection of Methanol

“…Meanwhile, the exposed crystals of 3D hierarchical‐structured metal oxides have also had a pivotal effect on the sensitivity and selectivity of gas sensors . A number of methods based on 3D hierarchical structures, such as diode, fluorescence, luminescence, and ellipsoidal nanospheres, have been employed for methanol detection. However, methanol sensors based on electrical resistance can achieve a detection limit of 5 ppm, but the selectivity of detection is always too low to meet the requirements of practical applications .…”