Layer-by-Layer Assembly of Metal-Organic Frameworks in Macroporous Polymer Monolith and Their Use for Enzyme Immobilization.
TL;DR: These new ZIF-8@monolith hybrids are used as solid-phase carriers for enzyme immobilization and the best of the conjugates enable very efficient digestion of proteins that can be achieved in mere 43 s.
Abstract: New monolithic materials comprising zeolitic imidazolate framework (ZIF-8) located on the pore surface of poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith previously functionalized with N-(3-aminopropyl)-imidazole have been prepared via a layer-by-layer self-assembly strategy. These new ZIF-8@monolith hybrids are used as solid-phase carriers for enzyme immobilization. Their performance is demonstrated with immobilization of a model proteolytic enzyme trypsin. The best of the conjugates enable very efficient digestion of proteins that can be achieved in mere 43 s.
Citations
More filters
TL;DR: It is demonstrated that a class of porous materials termed metal-organic frameworks (MOFs) can spontaneously form on protein-based hydrogels via a process analogous to natural matrix-mediated biomineralization, and that cells encapsulated within a crystalline MOF shell remain viable after exposure to a medium containing lytic enzymes.
Abstract: ConspectusMany living organisms are capable of producing inorganic materials of precisely controlled structure and morphology. This ubiquitous process is termed biomineralization and is observed in nature from the macroscale (e.g., formation of exoskeletons) down to the nanoscale (e.g., mineral storage and transportation in proteins). Extensive research efforts have pursued replicating this chemistry with the overarching aims of synthesizing new materials of unprecedented physical properties and understanding the complex mechanisms that occur at the biological–inorganic interface.Recently, we demonstrated that a class of porous materials termed metal–organic frameworks (MOFs) can spontaneously form on protein-based hydrogels via a process analogous to natural matrix-mediated biomineralization. Subsequently, this strategy was extended to functional biomacromolecules, including proteins and DNA, which have been shown to seed and accelerate crystallization of MOFs. Alternative strategies exploit co-precipita...
424 citations
TL;DR: A review of the characterization methodologies used for enzyme/MOF-immobilized enzymes can be found in this article, where the authors discuss enzyme protection via encapsulation, pore infiltration and surface adsorption and summarizes strategies to form multicomponent composites.
Abstract: Because of their efficiency, selectivity, and environmental sustainability, there are significant opportunities for enzymes in chemical synthesis and biotechnology. However, as the three-dimensional active structure of enzymes is predominantly maintained by weaker noncovalent interactions, thermal, pH, and chemical stressors can modify or eliminate activity. Metal-organic frameworks (MOFs), which are extended porous network materials assembled by a bottom-up building block approach from metal-based nodes and organic linkers, can be used to afford protection to enzymes. The self-assembled structures of MOFs can be used to encase an enzyme in a process called encapsulation when the MOF is synthesized in the presence of the biomolecule. Alternatively, enzymes can be infiltrated into mesoporous MOF structures or surface bound via covalent or noncovalent processes. Integration of MOF materials and enzymes in this way affords protection and allows the enzyme to maintain activity in challenge conditions (e.g., denaturing agents, elevated temperature, non-native pH, and organic solvents). In addition to forming simple enzyme/MOF biocomposites, other materials can be introduced to the composites to improve recovery or facilitate advanced applications in sensing and fuel cell technology. This review canvasses enzyme protection via encapsulation, pore infiltration, and surface adsorption and summarizes strategies to form multicomponent composites. Also, given that enzyme/MOF biocomposites straddle materials chemistry and enzymology, this review provides an assessment of the characterization methodologies used for MOF-immobilized enzymes and identifies some key parameters to facilitate development of the field.
252 citations
TL;DR: The use of metal-organic frameworks (MOFs) as immobilization matrices for enzymes as a platform for emerging applications is reported in this paper, where an overview of strategies developed to prepare enzyme-MOF biocomposites is presented.
Abstract: The use of metal–organic frameworks (MOFs) as immobilization matrices for enzymes as a platform for emerging applications is reported. In addition to an overview of strategies developed to prepare enzyme–MOF biocomposites, the features that render MOFs interesting matrices for bio-immobilization are highlighted along with their potential benefits beyond a solid-state support in the design of innovative biocomposites.
251 citations
TL;DR: In this paper, the use of metal-organic frameworks as supports for enzyme encapsulation and subsequent catalytic applications is discussed and the relative catalytic activities of the enzyme@MOF composites versus free enzymes are highlighted.
Abstract: Enzymes are natural catalysts which are highly selective and efficient. Given that enzymes have very intricate and delicate structures, they need to be stabilized and protected by a support material if they are to be used under challenging catalytic conditions. This highlight focuses on the use of metal–organic frameworks as supports for enzyme encapsulation and subsequent catalytic applications. De novo and post-synthetic methods of encapsulation are discussed and the relative catalytic activities of the enzyme@MOF composites versus free enzymes are highlighted.
213 citations
TL;DR: A review of the progress of enzyme immobilization on MOFs from different points, including various synthetic approaches, main characteristics, mechanism, improved performance and application of immobilized enzyme/MOFs is also discussed in this paper.
Abstract: Metal-organic frameworks (MOFs) have attracted tremendous interests of many researchers as a new kind of porous materials. Compared to conventional matrices, MOFs possess high surface area and porosity, thousands of various kinds and structures, abundant designable organic ligands and metal nodes. In recent years, more and more attention has been paid to using MOFs as the matrices for enzyme immobilization and different strategies have been explored extensively. To present a clear outline of this new field, this review systematically summarizes the progress of enzyme immobilization on MOFs (enzyme/MOFs) from different points, including various synthetic approaches, main characteristics, mechanism, improved performance and application of immobilized enzyme/MOFs. Finally, the prospect of enzyme/ MOFs is also discussed.
130 citations
References
More filters
TL;DR: This work has shown that highly porous frameworks held together by strong metal–oxygen–carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.
Abstract: The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.
8,013 citations
TL;DR: In this article, an organic dicarboxylate linker is used in a reaction that gives supertetrahedron clusters when capped with monocarboxyates.
Abstract: Open metal–organic frameworks are widely regarded as promising materials for applications1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 in catalysis, separation, gas storage and molecular recognition. Compared to conventionally used microporous inorganic materials such as zeolites, these organic structures have the potential for more flexible rational design, through control of the architecture and functionalization of the pores. So far, the inability of these open frameworks to support permanent porosity and to avoid collapsing in the absence of guest molecules, such as solvents, has hindered further progress in the field14,15. Here we report the synthesis of a metal–organic framework which remains crystalline, as evidenced by X-ray single-crystal analyses, and stable when fully desolvated and when heated up to 300?°C. This synthesis is achieved by borrowing ideas from metal carboxylate cluster chemistry, where an organic dicarboxylate linker is used in a reaction that gives supertetrahedron clusters when capped with monocarboxylates. The rigid and divergent character of the added linker allows the articulation of the clusters into a three-dimensional framework resulting in a structure with higher apparent surface area and pore volume than most porous crystalline zeolites. This simple and potentially universal design strategy is currently being pursued in the synthesis of new phases and composites, and for gas-storage applications.
6,778 citations
TL;DR: Inelastic neutron scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules indicates the presence of two well-defined binding sites (termed I and II), which are associated with hydrogen binding to zinc and the BDC linker, respectively.
Abstract: Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate) with a cubic three-dimensional extended porous structure adsorbed hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. Inelastic neutron scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules indicates the presence of two well-defined binding sites (termed I and II), which we associate with hydrogen binding to zinc and the BDC linker, respectively. Preliminary studies on topologically similar isoreticular metal-organic framework-6 and -8 (IRMOF-6 and -8) having cyclobutylbenzene and naphthalene linkers, respectively, gave approximately double and quadruple (2.0 weight percent) the uptake found for MOF-5 at room temperature and 10 bar.
4,284 citations
TL;DR: In all cases, enzyme engineering via immobilization techniques is perfectly compatible with other chemical or biological approaches to improve enzyme functions and the final success depend on the availability of a wide battery of immobilization protocols.
3,016 citations
TL;DR: A bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometer lateral dimensions and nanometer thickness is presented and opens the door to ultrathin MOF-polymer composites for various applications.
Abstract: The research leading to these results has received funding (J.G., B.S.) from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 335746, CrystEng-MOF-MMM. T.R. is grateful to TUDelft for funding. G.P. acknowledges the A. von Humboldt Foundation for a research grant. A.C., I.L. and F.X.L.i.X. thank Consolider-Ingenio 2010 (project MULTICAT) and the ‘Severo Ochoa’ programme for support. I.L. also thanks CSIC for a JAE doctoral grant.
1,649 citations