Gold nanoclusters encapsulated into zinc-glutamate metal organic frameworks for efficient detection of H2O2

Enhanced biochemical sensing using metallic nanoclusters integrated with metal-organic frameworks (NCs@MOFs): a comprehensive review

In biochemical sensing, substantial progress has been achieved in the design, development, and application of metallic nanoclusters (NCs) and metal-organic frameworks (MOFs) as distinct entities. Integration of these two nanostructured materials is a promising strategy to form innovative composites with improved properties. Some improvements include (i) supporting platform to minimize the aggregation of NCs and enhance the emission efficiency; (ii) dual-emitting NCs@MOFs from the fluorescent/non-fluorescent MOFs and/or fluorescent NCs; and (iii) stability enhancement. These improvements increase the sensitivity, signal-to-noise ratio, and color tonality, lower the limit of detection, and improve other analytical figures of merits. In this review, we outline the preparation methods of NCs@MOF composites with the improvements offered by them in the field of biochemical analysis. Analytical applications in different fields, such as bioanalysis, environmental monitoring and food safety, are presented. Finally, we address the challenges that remain in the development and application of these composites, such as ensuring stability, enhancing the fluorescence intensity, and improving selectivity and scalability. Furthermore, perspectives on future research directions in this rapidly evolving field are offered.

A nickel glutamate metal biomolecule framework

This paper describes the synthesis of a MbioF (Metal-biomolecule Framework) using glutamic acid and nickel carbonate as precursors. The direct action of glutamic acid (H2Glu) on basic nickel carbonate (NiCO3·2Ni(OH)2·4H2O) initially indicated the formation of a complex, [Ni(HGlu)2], which was then treated in a Teflon-lined stainless steel autoclave at 100 °C for 24 hours, resulting in the compound {[Ni(Glu)(H2O)]·H2O}n, with a yield of 43%. The resolution of the structure of this compound by single-crystal X-ray diffraction indicated that it belongs to the orthorhombic crystal system and space group P212121, with a structure analogous to those of the compounds {[Co(Glu)(H2O)]·H2O}n, {[Cu(Glu)(H2O)]·H2O}n and {[Zn(Glu)(H2O])·H2O}n described in the literature, with a molecular formula of C5H9NO5Ni·H2O, molar mass of 239.8379 g mol-1, parameters a, b and c with values of 7.0577(2) (Å), 10.2307(3) (Å) and 11.5350(4) (Å), and a volume of 837.219 Å3. This compound, which is an intensely green crystalline solid, was characterized by electron (UV-Vis) and vibrational spectroscopy in the Fourier Transform Infrared (FTIR) region, powder X-ray diffractometry (PXRD) and thermogravimetric analysis (TGA/DTA). The in vivo toxicity and in vitro antimicrobial activity of the complex and the Ni-MOF were tested. The two compounds presented no toxicity at a concentration of 5000 μg mL-1, and showed inhibitory activity at 64 μg mL-1 in 24 h and at 128 μg mL-1 in 48 h against the yeast Candida albicans.

Luminescent Guests Encapsulated in Metal-Organic Frameworks for Portable Fluorescence Sensor and Visual Detection Applications: A Review

Metal-organic frameworks (MOFs) have excellent applicability in several fields and have significant structural advantages, due to their open pore structure, high porosity, large specific surface area, and easily modifiable and functionalized porous surface. In addition, a variety of luminescent guest (LG) species can be encapsulated in the pores of MOFs, giving MOFs a broader luminescent capability. The applications of a variety of LG@MOF sensors, constructed by doping MOFs with LGs such as lanthanide ions, carbon quantum dots, luminescent complexes, organic dyes, and metal nanoclusters, for fluorescence detection of various target analyses such as ions, biomarkers, pesticides, and preservatives are systematically introduced in this review. The development of these sensors for portable visual fluorescence sensing applications is then covered. Finally, the challenges that these sectors currently face, as well as the potential for future growth, are briefly discussed.