Designing Metal-Chelator-like Traps by Encoding Amino Acids in Zirconium-Based Metal–Organic Frameworks

Abstract

Metal chelators and porous sorbents are two of the forefront technologies applied for the recovery and separation of hazardous and/or valuable metal ions from aqueous solutions (i.e., polluted water sources, metal-rich mining wastewaters, acid leachates, and so forth). The transfer of the metal coordination functions of metal chelators to chemically stable host materials had only limited success so far. Here, we report the installation of natural acids (i.e., malic acid, mercaptosuccinic acid, succinic acid, fumaric acid, and citric acid) and amino acids (i.e., histidine, cysteine, and asparagine) within a porous zirconium-based trimesate metal−organic framework (MOF), namely, MOF-808. Applying this strategy, we were able to produce a pore environment spatially decorated with multiple functional groups usually found in commercial chelator molecules. The chemical stability of the amino acid molecules installed by the solvent-assisted ligand exchange has been studied to delimitate the applicability window of these materials. The adsorption affinity of MOF-808@(amino)acids in static and column-bed configurations can be finetuned as a function of the amino acid residues installed in the framework. MOF-808(amino)acid columns can be applied efficiently both for water remediation of heavy metals and for the separation of metal ions with different acidities. For instance, the initial trends for the dispersion of rare-earth elements have been identified. Electron paramagnetic resonance and inelastic neutron scattering spectroscopy reveal that MOF-808@(amino)acids stabilize metal centers as isolated and clustered species in a coordination fashion that involves both the amine and thiol functionals and that affects the vibrational freedom of some of the chemical groups of the amino acid molecules. The metal-ion stabilization within amino acid-decorated MOFs opens the avenue for application for pseudo biocatalysis purposes in the near future.

On The Multiscale Structure and Morphology of PVDF‐HFP@MOF Membranes in The Scope of Water Remediation Applications

“…At this point, it has been proven that the in situ functionalization of the MOF-808 immobilized within the membrane with cysteine via water based SALI protocols is feasible. As previously reported by A. Valverde et al [58] incorporating cysteine functions with ─SH groups into the MOF-808 pore space strongly shifts its adsorption affinity to capture soft metal ions as Hg II . Indeed, as explained in the cited work, the immobilization of different amino acids into the pore space of MOF-808 endows the material of metal-complexing mechanisms where single or cooperative metal-binding modes five rise to the stabilization of isolated, clustered and even partially reduced species for some specific metals.…”

“…For the functionalization of the PVDF‐HFP@MOF‐808 membranes with cysteine, the procedure was similar to the one applied for the MOF‐808 particles functionalization reported in. [ 58 ] Hundred milligram membrane was immersed in 100 mL of a 0.05 m cysteine solution and heated at 60 °C for 24 h. Then, the membranes were washed with water twice and dried at room temperature for 24 h. The sorbent and composite membranes were fully characterized, as detailed in the Supporting Information.…”

Malic acid-coated iridium nanoparticle-induced cascade enzymatic reactions for norepinephrine detection

“…1D), and the telescopic vibrational peaks ν asy (COO) and ν sym (COO) of the carboxylate group of MA can be observed at 1595 cm −1 and 1348 cm −1 . 28–30 The difference between the peak positions (Δ ν ) corresponds to the coordination mode between the metal ions and the carboxylate. 31 The value of Δ ν is 235 cm −1 , which implied that the carboxylate group of MA forms a single-type coordination on the surface of the IrNPs.…”

Highlighting Recent Research from Latin America in Chemistry of Materials

“…Porous materials continue to be an area of priority, with metal organic framework (MOF) materials being both studied and highlighted in a recent Up & Coming Perspective within the journal, the latter contribuion from Ibarra and co-workers. − Both the porosity of these materials and the chemical nature of the metal ions and organic linker molecules bring functionality. For example, Bof Bufon, Paes Leme, and co-workers built an electrochemical biosensor for detection of protein–protein interactions based on the zeolitic imidazole framework ZIF-8 serving as the transducer, and while not focused on MOFs, Crespilho and co-workers provided an excellent Perspective on electrochemical biosensing recently .…”

“…For example, Bof Bufon, Paes Leme, and co-workers built an electrochemical biosensor for detection of protein–protein interactions based on the zeolitic imidazole framework ZIF-8 serving as the transducer, and while not focused on MOFs, Crespilho and co-workers provided an excellent Perspective on electrochemical biosensing recently . MOFs were also designed for ammonia capture and water remediation of heavy metal ions, while synergy between the porosity and soft properties of MOFs was also shown to provide selectivity for adsorbates of different polarities . Beyond MOFs, porous carbon materials have a rich history for their adsorbent properties, and their design was greatly accelerated by the application of machine learning and natural language processing to over 10 000 scientific articles, gaining understanding of how synthesis parameters influence their properties …”