Construction of a dual-response luminescent metal-organic framework with excellent stability for detecting Fe3+ and antibiotic with high selectivity and sensitivity

A Comprehensive Review on the Use of Metal–Organic Frameworks (MOFs) Coupled with Enzymes as Biosensors

Several studies have shown the development of electrochemical biosensors based on enzymes immobilized in metal–organic frameworks (MOFs). Although enzymes have unique properties, such as efficiency, selectivity, and environmental sustainability, when immobilized, these properties are improved, presenting significant potential for several biotechnological applications. Using MOFs as matrices for enzyme immobilization has been considered a promising strategy due to their many advantages compared to other supporting materials, such as larger surface areas, higher porosity rates, and better stability. Biosensors are analytical tools that use a bioactive element and a transducer for the detection/quantification of biochemical substances in the most varied applications and areas, in particular, food, agriculture, pharmaceutical, and medical. This review will present novel insights on the construction of biosensors with materials based on MOFs. Herein, we have been highlighted the use of MOF for biosensing for biomedical, food safety, and environmental monitoring areas. Additionally, different methods by which immobilizations are performed in MOFs and their main advantages and disadvantages are presented.

A Water-Stable Tb-MOF As a Rapid, Accurate, and Highly Sensitive Ratiometric Luminescent Sensor for the Discriminative Sensing of Antibiotics and D2O in H2O

The design and development of self-calibrating ratiometric luminescent sensors for the fast, accurate, and sensitive discrimination and determination of pollutants in wastewater is highly desirable for public and environmental health. Herein, a 3D porous Tb(III)-based metal-organic framework (MOF), {[Tb(HL)(H₂O)₂]·x(solv)}_n (1), was facilely synthesized using a urea-functionalized tetracarboxylate ligand, 5,5'-(((1,4-phenylenebis(azanediyl))bis(carbonyl))bis(azanediyl))diisophthalic acid (H₄L). The activated framework showed a good water stability in both aqueous solutions at a wide pH range of 2-14 and simulated antibiotic wastewaters. Interestingly, this Tb-MOF exhibited dual luminescence owing to the partial energy transfer from the antenna H₄L to Tb³⁺. More importantly, activated 1 (1a) that was dispersed in water showed a fast, accurate, and highly sensitive discrimination ability toward antibiotics with a good recyclability, discriminating three different classes of antibiotics from each other via the quenching or enhancement of the luminescence and tuning the emission intensity ratio between the H₄L ligand and the Tb³⁺ center for the first time. Simultaneously, 1a is a ratiometric luminescent sensor for the rapid, accurate, and quantitative discrimination of D₂O from H₂O. Furthermore, this complex was successfully used for the effective determination of antibiotics and D₂O in real water samples. This work indicates that 1a represents the first ever MOF material for the discriminative sensing of antibiotics and D₂O in H₂O and promotes the practical application of Ln-MOF-based ratiometric luminescent sensors in monitoring water quality and avoiding any major leak situation.

Applications of MOFs as Luminescent Sensors for Environmental Pollutants

The environmental pollution has become a serious issue because the pollutants can cause permanent damage to the DNA, nervous system, and circulating system, resulting in various incurable diseases, such as organ failure, malformation, angiocardiopathy, and cancer. The effective detection of environmental pollutants is urgently needed to keep them far away from daily life. Among the reported pollutant sensors, luminescent metal-organic frameworks (LMOFs) with tunable structures have attracted remarkable attention to detect the pollutants because of their excellent selectivity, sensitivity, and recyclability. Although lots of metal-organic framework (MOF)-based luminescent sensors have been summarized and discussed in previous reviews, the detection of environmental pollutants, especially radioactive ions and heavy metal ions, still have not been systematically presented. Here, the sensing mechanisms and construction principles of luminescent MOFs are discussed, and the state-of-the-art MOF-based luminescent sensors of environmental pollutants, including pesticides, antibiotics, explosives, VOCs, toxic gas, toxic small molecules, radioactive ions, and heavy metal ions are highlighted. This comprehensive review may further guide the development of luminescent MOFs and promote their practical applications for sensing environmental pollutants.

State of the art methods and challenges of luminescent metal–organic frameworks for antibiotic detection

This review focuses on recent developments in the design and synthesis of luminescence MOFs for monitoring antibiotics.

Multi-responsive chemosensing and photocatalytic properties of three luminescent coordination polymers derived from a bifunctional 1,1′-di(4-carbonylphenyl)-2,2′-biimidazoline ligand

Three 3D Zn^II/Cd^II CPs were synthesized to act as multiresponsive luminescent sensors for Fe³⁺, Cr₂O₇²⁻ and NZF antibiotic. The photocatalytic studies indicate that the CPs 1–3 have good photocatalytic capability in degradation of MB.