Dual-emissive EY/UiO-66-NH2 as a ratiometric probe for turn-on sensing and cell imaging of hypochlorite

MOFs as versatile scaffolds to explore environmental contaminants based on their luminescence bustle

Metal-Organic Frameworks (MOFs) with luminescent properties hold significant promise for environmental remediation. This review critically examines recent research on these materials design, synthesis, and applications, mainly focusing on their role in combating environmental pollutants. Through a comprehensive analysis of metal ions, ligands, and framework compositions, the review discusses the importance of tailored design and synthesis approaches in achieving desired luminescent characteristics. Key findings highlight the effectiveness of luminous MOFs as fluorescent sensors for a wide range of contaminants, including heavy metals, reactive species, antibiotics, and explosives. Considering all this, the review discusses future research needs and opportunities in the field of luminous MOFs. It emphasizes the importance of developing multifunctional materials, refining design methodologies, exploring sensing mechanisms, and ensuring environmental compatibility, scalability, and affordability. By providing insights into the current state of research and outlining future directions, this review is a valuable resource for researchers seeking to address environmental challenges using MOF-based solutions.

Post-synthetic modified luminescent metal-organic framework for the detection of berberine hydrochloride in a traditional Chinese herb

In this work, a novel fluorescence sensor UiO-66-PSM based on post-synthetic modified metal-organic frameworks was prepared for the detection of berberine hydrochloride (BBH) in the traditional Chinese herb Coptis. UiO-66-PSM was synthesized by a simple Schiff base reaction with UiO-66-NH2 and phthalaldehyde (PAD). The luminescence quenching can be attributed to the photo-induced electron transfer process from the ligand of UiO-66-PSM to BBH. The UiO-66-PSM sensor exhibited fast response time, low detection limit, and high selectivity to BBH. Moreover, the UiO-66-PSM sensor was successfully applied to the quantitative detection of BBH in the traditional Chinese herb Coptis, and the detection results obtained from the as-fabricated fluorescence sensing assay were consistent with those of high-performance liquid chromatography (HPLC), indicating that this work has potential applicability for the detection of BBH in traditional Chinese herbs.

Efficient Eu3+-Integrated UiO-66 Probe for Ratiometric Fluorescence Sensing of Styrene and Cyclohexanone

The development of probes with sensitive and prompt detection of volatile organic compounds (VOCs) is of great importance for protecting human health and public security. Herein, we successfully prepared a series of bimetallic lanthanide metal-organic framework (Eu/Zr-UiO-66) by incorporating Eu³⁺ for fluorescence sensing of VOCs (especially styrene and cyclohexanone) using a one-pot method. Based on the multiple fluorescence signal responses of Eu/Zr-UiO-66 toward styrene and cyclohexanone, a ratiometric fluorescence probe using (I₆₁₇/I₃₂₀) and (I₆₁₇/I₃₃₀) as output signals was developed to recognize styrene and cyclohexanone, respectively. Benefitting from the multiple fluorescence response, the limits of detection (LODs) of Eu/Zr-UiO-66 (1:9) for styrene and cyclohexanone were 1.5 and 2.5 ppm, respectively. These are among the lowest reported levels for MOF-based sensors, and this is the first known material for fluorescence sensing of cyclohexanone. Fluorescence quenching by styrene was mainly owing to the large electronegativity of styrene and fluorescence resonance energy transfer (FRET). However, FRET was accounted for fluorescence quenching by cyclohexanone. Moreover, Eu/Zr-UiO-66 (1:9) exhibited good anti-interference ability and recycling performance for styrene and cyclohexanone. More importantly, the visual recognition of styrene and EB vapor can be directly realized with the naked eyes using Eu/Zr-UiO-66 (1:9) test strips. This strategy provides a sensitive, selective, and reliable method for the visual sensing of styrene and cyclohexanone.