UiO-66, as a member of the MOFs families, is widely employed in sensing, drug release, separation, and adsorption due to its large specific surface area, uniform pore size, easy functionalization, and excellent stability. Especially in electrochemical biosensors, UiO-66 has demonstrated excellent adsorption capacity and response signal, which significantly improves the sensitivity and specificity of detection. However, the existing application research remains in its infancy, lacking systematic methods, and recycling utilization and exclusive sensing of UiO-66 still require further improvement. Therefore, one of the present research objectives is to explore the breakthrough point of existing technologies and optimize the performance of UiO-66-based electrochemical biosensors (UiO-66-EBs). In this work, we summarized current experimental methods and detection mechanisms of UiO-66-EBs in environmental detection, food safety, and disease diagnosis, analyzed the existing problems, and proposed some suggestions to provide new ideas for future research.

Extensive use and disposal of 2,4,6-trinitrotoluene (TNT), a primary constituent of explosives, pollutes the environment and causes severe damage to human health. Complete mineralization of TNT via bacterial degradation has recently gained research interest as an effective method for the restoration of contaminated sites. Here, screening for TNT degradation by six selected bacteria revealed that Buttiauxella sp. S19-1, possesses the strongest degrading ability. Moreover, BuP34O (a gene encoding for protocatechuate 3,4-dioxygenase—P34O, a key enzyme in the β-ketoadipate pathway) was upregulated during TNT degradation. A knockout of BuP34O in S19-1 to generate S-M1 mutant strain caused a marked reduction in TNT degradation efficiency compared to S19-1. Additionally, the EM1 mutant strain (Escherichia coli DH5α transfected with BuP34O) showed higher degradation efficiency than DH5α. Gas chromatography mass spectrometry (GC-MS) analysis of TNT degradation by S19-1 revealed 4-amino-2,6-dinitrotolune (ADNT) as the intermediate metabolite of TNT. Furthermore, the recombinant protein P34O (rP34O) expressed the activity of 2.46 µmol/min·mg. Our findings present the first report on the involvement of P34O in bacterial degradation of TNT and its metabolites, suggesting that P34O could catalyze downstream reactions in the TNT degradation pathway. In addition, the TNT-degrading ability of S19-1, a Gram-negative marine-derived bacterium, presents enormous potential for restoration of TNT-contaminated seas.

A rosebengal-modified nanoporous structure was designed and constructed. This composite structure consisted of an organic sensitizer based on rosebengal and a supporting host of rare earth metal-organic-framework (MOF). It was identified by means of its x-ray diffraction (XRD) pattern, Infrared (IR) spectra, thermal stability and photophysical measurements. Its absorption was increased by 2,4,6-trinitrophenol. Its rosebengal emission was proportionally increased. But its rare earth emission was well-preserved, offering ratiometric signals. These two sensing modes exhibited linear response and good selectivity with a limit of detection (LOD) of 1.9 μM. Its sensing nature was confirmed as the combination of increased rosebengal emission and rare earth emission quenching effect triggered electron-deficient molecules. This nanoporous structure was superior to traditional ones owing to its double sensing modes.