Encapsulation of biomacromolecules in metal− organic frameworks (MOFs) can preserve biological functionality in harsh environments. Despite the success of this approach, termed biomimietic mineralization, limited consideration has been given to the chemistry of the MOF coating. Here, we show that enzymes encapsulated within hydrophilic MAF-7 or ZIF-90 retain enzymatic activity upon encapsulation and when exposed to high temperatures, denaturing or proteolytic agents, and organic solvents, whereas hydrophobic ZIF-8 affords inactive catalase and negligible protection to urease.

Due to 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 non-covalent 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 non-covalent 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 multi-component 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. CONTENTSMOF-based enzyme biocomposite compositions and the concept of encapsulation 3.MOF-based enzyme biocomposites formed via encapsulation 3.1.Templating methods 3.2.One-pot embedding (non-templated) 3.3.Parameters influencing the chemistry of enzyme@MOF biocomposites 3.3.1. Additives 3.3.2.Enzyme suface chemistry 3.3.3.MOF precusors and structures 3.4.Alternative synthesis strategies 4.Infiltration (post insertion of enzymes in preformed MOFs) 4.1.Early results and the advantages of MOFs for infiltration 4.2.Tuning the framework structure in infiltrated enzyme@MOF biocomposites 4.3.Towards applications of infiltrated enzyme@MOFs 5.Surface bound enzymes 5.1. Immobilization via physical adsorption 5.2. Immobilization via coordinate bonds 5.3. Immobilization via covalent bonding 5.4. Enzymatic activity upon surface-immobilization 6. Multicomponent biocomposites 7. Characterization of MOF immobilized enzymes 7.1. Overview 7.2. Key immobilization parameters 7.3. One-pot enzyme MOF formation 7.4. Highlights of MOF-immobilized enzyme performance 7.4.1. Experimental determination of key immobilization parameters 7.4.1.1. Determination of protein concentrations 7.4.1.2. Activity determination 7.4.2. Advanced characterization of immobilized enzymes 7.4.2.1. Apparent enzyme kinetics 7.4.2.2. Structural analysis and localization o...

The new agreement specifically addresses what authors can do with different versions of their manuscripte.g. use in theses and collections, teaching and training, conference presentations, sharing with colleagues, and posting on websites and repositories. The terms under which these uses can occur are clearly identified to prevent misunderstandings that could jeopardize final publication of a manuscript (Section II, Permitted Uses by Authors).

The new agreement specifically addresses what authors can do with different versions of their manuscripte.g. use in theses and collections, teaching and training, conference presentations, sharing with colleagues, and posting on websites and repositories. The terms under which these uses can occur are clearly identified to prevent misunderstandings that could jeopardize final publication of a manuscript (Section II, Permitted Uses by Authors).

Defect concentrations and their compensating groups have been systematically tuned within UiO-66 frameworks by using modified microwave-assisted solvothermal methods. Both of these factors have a pronounced effect on CO2 and H2O adsorption at low and high pressure.