Work

Tailored UiO-66-X on quartz crystal microbalance for PPB-level toluene detection

Year: 2025

Type: article

Abstract: Metal-organic frameworks (MOFs) are ideal for fabricating sensors due to their well-defined and highly tailored nano-porous architectures. Herein, a series of zirconium-based MOFs (UiO-66 and UiO-66-X, X=NH2, Br, NO2) with functionalized ligands and uniform morphology were synthesized by incorporating L-histidine as a structural modulator. Subtle changes in responses are achieved by altering the MOFs guest adsorption affinities through the incorporation of functional groups into its linkers. The UiO-66 and UiO-66-X material, used in a quartz crystal microbalance (QCM) gravimetric sensor, enables the ultrasensitive detection of toluene at room temperature (25°C) and fixed humidity (55% RH). Compared with UiO-66, UiO-66-Br and UiO-66-NO2, UiO-66-NH2 exhibited superior selectivity toward toluene vapor owing to the presence of proper molecular size and π-π stacking/hydrogen bonding between the microporous framework of UiO-66-NH2 and toluene molecules. Furthermore, the UiO-66-NH2 based QCM sensor demonstrated exceptional sensitivity (190 Hz @ 10 ppm) and short response/recovery time (less than 6/21 s), achieving detection limit as low as 50 ppb for toluene under air ambient conditions. This work provides valuable insights into the rational design of ligand-functionalized MOFs for gas sensing applications.

Source: Microchemical Journal

DOI: 10.1016/j.microc.2025.116251