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Covalent triazine frameworks (CTFs) and their derived N-doped carbons have attracted tremendous attention due to their wide application in energy conversion and storage in the past few years. However, previous interests mainly focused on development of new building blocks and optimizing the synthetic conditions. Taking advantage of the isometric building blocks to control the porous structure and to fundamentally understand the structure-property relationship are rarely reported. In this work, two isometric building blocks are used to produce isometric CTFs with controllable pore geometries. As-prepared CTF with non-planar hexagonal pores demonstrates higher surface area, larger pore volume and richer N content in comparison with the planar CTF. After pyrolysis, corresponding N-doped carbons derived from non-planar porous CTF at 900 oC exhibit admirable catalytic activity for oxygen reduction in alkaline media (half-wave potential: 0.86 V; Tafel slope: 65 mV dec-1), owing to the larger pore volume together with rich pyridinic and quaternary N species. When assembled into a zinc-air battery, as-made electrocatalysts show high capacity up to 651 mAh g-1 and excellent durability. This work design two kinds of tailoring and scalable CTFs and their-derived porous carbons material, which are highly efficient electrocatalysts for energy conversion and storage.

Engineering of enzyme microenvironment can surprisingly boost the apparent activity. However, the underlying regulation mechanism is not well-studied at a molecular level so far. Here, we present a modulation of two model enzymes of cytochrome c (Cty C) and d-amino acid oxidase (DAAO) with opposite pH-activity profiles using ionic polymers. The operational pH of poly (acrylic acid) modified Cyt C and polyallylamine modified DAAO was extended to 3–7 and 2–10 where the enzyme activity was larger than that at their optimum pH of 4.5 and 8.5 by 106% and 28%, respectively. The cascade reaction catalyzed by two modified enzymes reveals a 1.37-fold enhancement in catalytic efficiency compared with their native counterparts. The enzyme activity boosting is understood by performing the UV–vis/CD spectroscopy and molecular dynamics simulations in the atomistic level. The increased activity is ascribed to the favorable microenvironment in support of preserving enzyme native structures nearby cofactor under external perturbations.

Because of their ability to selectively bind to a target protein, copolymer nanoparticles (NPs) containing a selected combination of hydrophobic and charged groups have been frequently reported as potent antibody-like analogues. However, due to the intrinsic disorder of the copolymer NP in terms of its random monomer sequence and the cross-linked copolymer matrix, the copolymer NP is indeed strikingly different from a well-folded protein antibody and the complexation between the copolymer NP and a target protein is likely not due to a lock-key type of interaction but possibly due to a novel and unexplored molecular mechanism. Here, we study a key biomarker protein, vimentin, interacting with a set of random copolymer chains using implicit-water explicit-ion coarse-grained (CG) molecular dynamics (MD) simulations along with biolayer interferometry (BLI) analysis. Due to the charge and hydrophobicity anisotropy on the vimentin dimer (VD) surface, a set of bound copolymers are found inhomogenously adsorbed on the VD, with energetic heterogeneity for different binding sites and cooperative effect in the adsorption. Increasing the charge or hydrophobicity of the copolymer may have different consequences on the adsorption. In this study, we found that with more copolymer charges, the protein coverage increases for copolymers of low hydrophobicity and decreases of high hydrophobicity, which is explained by the distribution and size of various functional patches on the VD in loading those copolymers. Employing a coverage-dependent Langmuir model, we propose a simulation protocol to address the full profile of the copolymer binding free energy through the fit to the simulated binding isotherm. The obtained results correlate well with those from the BLI experiment, indicating the significance of this method for the rational design of the copolymer NP with engineered protein binding affinity.

As the most representative family of proteinases related to tumorigenesis, matrix metalloproteinase-9 (MMP-9) represents a key player in cancer cell migration and regulation of the tumor microenvironment. The inhibition of MMP-9 activity has been pursued as a target for anticancer therapy. However, most synthetic MMP-9 inhibitors have failed in clinical trials because of their lack of selectivity. Here, an abiotic mimic based on molecularly imprinted nanoparticles has been designed as an inhibitor for MMP-9. To attain fast mass transfer and facilitate multifunctional roles, we synthesized the imprinted polymer thin layer on the surface of gold nanorods by reversible addition-fragmentation chain transfer polymerization using MMP-9 as the template, which captures MMP-9 selectively and inhibits its activity by providing steric hindrance to the activity-related domain of MMP-9. In vitro cell experiments and in vivo studies in mice demonstrate that the imprinted artificial antibody suppresses the migration and growth of metastatic tumors. The tumor growth inhibition rate reaches up to 54 ± 15%. Compared with the typical photothermal therapy induced by gold nanorods, the use of MMP-9-imprinted synthetic antibody could better inhibit the lung tumor metastasis by quenching the enzyme activity of MMP-9. This study offers a new paradigm in the engineering of imprinted nanoparticles as inhibitors for cancer therapy.

Ultrathin polydopamine microcapsules with hierarchical structure and porosity were prepared for the immobilization of multienzymes using metal-organic framework (MOF) as the template. The multienzyme/MOF composite was first prepared using a “one-pot” co-precipitation approach via the coordination and self-assembly of zinc ions and 2-methylimidazole in the presence of enzymes. The obtained nanoparticles were then coated with polydopamine thin layer through the self-polymerization of dopamine under alkaline condition. The polydopamine microcapsules with an ultrathin shell thickness of ~ 48 nm were finally generated by removing the MOF template at acidic condition. Three enzymes were encapsulated in PDA microcapsules including carbonic anhydrase (CA), formate dehydrogenase (FateDH), and glutamate dehydrogenase (GDH). FateDH that catalyzed the main reaction of CO2 reduction to formic acid retained 94.7% activity of equivalent free FateDH. Compared with free multienzymes, the immobilized ones embedded in PDA microcapsules exhibited 4.5-times higher of formate production and high catalytic efficiency with a co-factor-based formate yield of 342%.

New biocatalytic systems with enhanced enzymatic performances have been rationally designed based on the coordination and self-assembly of β-galactosidase with its Mg2+ allosteric effector in the p...

Biomarkers are significant indicators to assist the early diagnosis of diseases and assess the therapeutic response. However, due to the low abundance of biomarkers in complex biological fluids, it is highly desirable to explore efficient techniques to attain their selective recognition and capture before the detection. Molecularly imprinted monoliths integrate the high selectivity of imprinted polymers and the rapid convective mass transport of monoliths, and as a result, are promising candidates to achieve the specific enrichment of biomarkers from complex samples. This review summarizes the various imprinting approaches for the preparation of molecularly imprinted monoliths. The state-of-art advances as an effective platform for applications in the selective capture of biomacromolecules related biomarkers were also outlined.

Two frontier crystalline porous framework materials, namely, metal‐organic frameworks (MOFs) and covalent organic frameworks (COFs), have been widely explored owing to their outstanding physicochemical properties. While each type of framework has its own intrinsic advantages and shortcomings for specific applications, combining the complementary properties of the two materials allows the engineering of new classes of hybrid porous crystalline materials with properties superior to the individual components. Since the first report of MOF/COF hybrid in 2016, it has rapidly evolved as a novel platform for diverse applications. The state‐of‐art advances in the various synthetic approaches of MOF/COF hybrids are hereby summarized, together with their applications in different areas. Perspectives on the main challenges and future opportunities are also offered in order to inspire a multidisciplinary effort toward the further development of chemically diverse, multi‐functional hybrid porous crystalline materials., This review provides a systematic summary of the synthetic protocols of hybrid materials based on metal‐ organic frameworks (MOFs) and covalent organic frameworks (COFs), as well as an overview of their application in various fields. Together with perspectives on the main challenges and opportunities, the timely review should inspire future research efforts toward the rational development of functional MOF/COF hybrids.

Covalent organic frameworks (COFs), a burgeoning class of crystalline porous materials constructed by covalently connecting organic building blocks, have garnered tremendous attention. The predominant solvothermal synthesis of COFs usually requires high temperature and long reaction times (three days or longer), which creates substantial obstacles for their accelerated discovery and exploration in practical applications. Hence, the expeditious synthesis of COFs without compromising their inherent properties is exceedingly appealing from the viewpoint of cost, time, and energy footprint. To overcome the sluggishness of the synthesis, considerable efforts have been invested in the rapid synthesis of high-quality COFs through innovations in energy source, catalyst, solvent, monomer, nucleation, and workup activation, leading to a drastic reduction of reaction time from multiple days to a few hours, and even to seconds in some cases. In this contribution, we provide a comprehensive overview of the advances in expediting the synthesis science of COFs. Though a nascent effort, six prevalent strategies have been identified for the rapid synthesis of COFs, which have led to intriguing applications in a diverse range of areas including gas adsorption, separation, heterogeneous catalysis, environmental remediation, and photodynamic therapy. We also outline the major challenges and perspectives on the future directions empowered by expeditious COF synthesis.

Traditional films cannot fully adapt to industrial applications and to intensified processes. Advanced mixed-matrix membranes comprising metal-organic frameworks (MOF) embedded in a polymer matrix have been developed with the goal of breaking the trade-off effect of traditional polymer membranes and achieving separation performance beyond Robeson's upper limit. The key challenges in the fabrication of MOF-based mixed-matrix membranes are an enhancement in compatibility between the inorganic filler and the polymer matrix, elimination of the irregular morphology and non-selective interfacial defects, and further improvement in the gas-separation performance. This review summarizes the recent advances in protocols and strategies in terms of designing interfacial interactions to enhance the MOF/polymer interface compatibility. This review aims at providing some meaningful insights into preparing MOF-based mixed-matrix membranes targeting ideal interfacial morphology and leading to excellent gas-separation performance.

Heparin is a highly sulfated polysaccharide, applied in clinic for treatment of thrombotic diseases. The biological activity is closely related to its molecular structure e.g. compositions of disaccharides and oligosaccharides units. The classical method to isolate the oligosaccharides after depolymerization by heparinases or nitrous acid I s by size exclusion chromatography which is a time-consuming process. In this study, we explored the possibility for rapid separation of oligosaccharides using a novel polymer material. The magnetic thermoresponsive molecularly imprinted polymers (MIPs) were synthesized using heparin disaccharide as a template, AEM, NIPAAm, and AAm as functional monomer, and MBAA as crosslinker by surface radical polymerization in an aqueous media. Incubation of the MIP with hepairn oligosaccharides demonstrated specific binding to the template molecule. This binding to the targeted molecule was affected by reaction temperature with regard to binding capacity and specificity. The recognition specificity and selectivity can be modulated by varying the compositions of multi-functional monomers. The pseudo-second-order kinetic model and Langmuir isotherm model provide the best fit to the equilibrium adsorption of heparin disaccharides by MIPs. The results suggest that the new material can be used for rapid separation of di- and tetra-saccharides of heparin, which can also be adapted to the applications for isolation of oligosaccharides from other polysaccharides, e.g. heparan sulfate and chondoriting sulfate.

A facile and simple chelation assisted in-situ growth approach for the preparation of thin uniform metal organic framework composite membranes has been developed. Coherent zeolite imidazolate framework ZIF-7 and ZIF-67 layers were successfully grown on porous polypropylene substrate covered with metal-chelating polyaniline interface layer. These membranes exhibited a H2 permeance of 1.6 × 10−7 mol m−2 s−1 Pa−1 and an ideal H2/CO2 separation factor of 7.9. The incorporation of the second organic linker 2-aminobenzimidazole in the ZIF-7 framework afforded ZIF-7-NH2 layer enabling gate-opening and flexibility. This new hybrid ZIF-7-NH2 membrane featured a significantly increased H2 permeance of 4.9 × 10−6 mol m−2 s−1 Pa−1 and an ideal H2/CO2 separation factor of 10.6.

Summary The preparation of flawless and defect-free mixed matrix membranes (MMMs) comprising metal-organic framework (MOF) and polymer is often difficult owing to the poor MOF/polymer interface compatibility. Herein, we present the synthesis of an important family of pillared-layered MOFs with polymerizable moieties based on the parent structure [Zn2L2P]n [L = vinyl containing benzenedicarboxylic acid linkers; P = 4,4′-bipyridine (bipy)]. The crystalline structures of polymerizable MOFs were analyzed using single-crystal X-ray crystallography. The presence of reactive double bonds in MOFs was verified by the successful thiol-ene click reaction with sulfhydryl compounds. The subsequent copolymerization of polymerizable MOFs with organic monomers produced mixed matrix membranes with enhanced MOF/polymer interfacial adhesion that enabled good separation efficiency of CO2 from flue gas. This strategy provides a stimulating platform to the preparation of highly efficient MMMs that are capable of mitigating energy consumption and environment issues., Graphical abstract, Highlights • A new class of vinyl-containing MOFs was constructed for the separation of CO2 and N2. • The structure of BUCT MOFs were analyzed by single-crystal X-ray crystallography. • The C=C double bonds of BUCT MOFs can serve as polymerizable groups with high activity. • BUCT-2 based MMM exhibited a superior CO2/N2 selectivity of 41.6.

Molecularly imprinted polymers, developed 50 years ago, have garnered enormous attention as receptor-like materials. Lately, molecularly imprinted polymers have been employed as a specific target tool in favor of cancer diagnosis and therapy by the selective recognition of tumor cells. Although the molecular imprinting technology has been well-innovated recently, the cell still remains the most challenging target for imprinting. In this review, we summarize the advances in the synthesis of molecularly imprinted polymers suitable for the selective recognition of tumor cells. Through a sustained effort, three strategies have been developed including peptide-imprinting, polysaccharide-imprinting, and whole-cell imprinting, which have resulted in inspiring applications in effective cancer diagnosis and therapy. The major challenges and perspectives on the further directions related to the synthesis of molecularly imprinted polymers were also outlined.

Mixed-matrix membranes containing covalent-organic frameworks (COFs) and polymer phase hold great promise for effective and economical CO2 separation due to the robust and tunable porous framework structures of COFs. However, the pore sizes of most reported COFs are larger than gas molecules. Meanwhile, the undesired COF aggregation impedes the preparation of continuous and defect-free membranes. Herein, we describe a new strategy for the facile manufacture of 2D-COF based mixed-matrix membranes via in situ “bottom-up” growth approach which involved the admixing of COF precursors with PEO monomers at the molecular level in a solvent-free system. Free radical polymerization allowed the formation of polymer membranes containing well-dispersed COF precursors. The 2D-COFs with uniform distributions were further generated via the covalent linkages of precursors within the cross-linked polymer network under microwave assisted Zincke reaction. The resulting mixed-matrix membrane exhibited a remarkable permeability of 803.9 barrer for CO2 and selectivities of 61.4, 19.8, 15.0 for CO2/N2, CO2/CH4, CO2/H2, respectively, exceeding the known upper-bound limits reported for polymer membranes. Meanwhile, the membranes displayed a one-month stability confirming its exceptional long-term operational stability and great potential for industrial gas separations.

The key in preparing mixed matrix membranes for the desired gas separation is to rationally select a suitable combination of inorganic fillers and polymers and to develop fabrication techniques enabling formation of a continuous inorganic phase with dual transport pathway. Herein, we report the facile design of flexible poly[poly(ethylene glycol) methacrylate-co-poly(ethylene glycol) dimethacrylate] membranes containing metal organic frameworks UiO-66 prepared from zirconium chloride and 2-aminoterephthalic and terephthalic acid varying in contents, shapes, and sizes. The surface chemistry effects of both polymer matrix and MOFs on permeability and selectivity were investigated. The bare polymer membrane exhibited a permeability for CO2 of around 117 barrer and a selectivity of up to 15. Addition of glycidyl methacrylate in the polymerization mixture led to membranes that were modified with hexamethylenediamine to provide for basicity. However, this modification did not improve performance of the membrane...

The main challenges in multienzymatic cascade reactions for CO2 reduction are the low CO2 solubility in water, the adjustment of substrate channeling, and the regeneration of co-factor. In this study, metal-organic frameworks (MOFs) were prepared as adsorbents for the storage of CO2 and at the same time as solid supports for the sequential co-immobilization of multienzymes via a layer-by-layer self-assembly approach. Amine-functionalized MIL-101(Cr) was synthesized for the adsorption of CO2. Using amine-MIL-101(Cr) as the core, two HKUST-1 layers were then fabricated for the immobilization of three enzymes chosen for the reduction of CO2 to formate. Carbonic anhydrase was encapsulated in the inner HKUST-1 layer and hydrated the released CO2 to HCO3-. Bicarbonate ions then migrated directly to the outer HKUST-1 shell containing formate dehydrogenase and were converted to formate. Glutamate dehydrogenase on the outer MOF layer achieved the regeneration of co-factor. Compared with free enzymes in solution using the bubbled CO2 as substrate, the immobilized enzymes using stored CO2 as substrate exhibited 13.1-times higher of formate production due to the enhanced substrate concentration. The sequential immobilization of enzymes also facilitated the channeling of substrate and eventually enabled higher catalytic efficiency with a co-factor-based formate yield of 179.8%. The immobilized enzymes showed good operational stability and reusability with a cofactor cumulative formate yield of 1077.7% after 10 cycles of reusing.

Magnetic multi-enzyme nanosystems have been prepared via co-precipitation of enzymes and metal–organic framework HKUST-1 precursors in the presence of magnetic Fe3O4 nanoparticles. The spatial co-localization of two enzymes was achieved using a layer-by-layer positional assembly strategy. Glucose oxidase (GOx) and horseradish peroxidase (HRP) were used as the model enzymes for cascade biocatalysis. By controlling the spatial positions of enzymes, three bienzyme nanosystems GOx@HRP@HKUST-1@Fe3O4, GOx–HRP@HKUST-1@Fe3O4 and HRP@GOx@HKUST-1@Fe3O4 were prepared in which GOx and HRP containing layers were in close proximity, either encapsulated in the HKUST-1 inner layer, or immobilized on the HKUST-1 outer shell, or randomly distributed in the two MOF layers. Their properties were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, and zeta potential measurements. The highest activity was observed at pH = 6 and a temperature of 20 °C. Thanks to the favorable positioning of enzymes, the GOx@HRP@HKUST-1@Fe3O4 nanosystem revealed superior kinetics with a Michaelis constant Km = 0.8 mmol L−1 and the maximum reaction rate Vmax = 11.3 μmol L−1 min−1. The enzyme–HKUST-1 conjugates exhibited remarkably high operational stability compared to the free enzymes. This work provides a facile and versatile approach to spatially organized multienzyme systems with well-defined nanostructures and greatly enhanced the overall biocatalytic efficiency.

Nanoporous polymers with permanent porous structure and high surface areas of up to 2084 m2/g have been prepared via hypercrosslinking of polystyrene copolymers using Friedel-Crafts alkylation reaction. The hypercrosslinked polymers were prepared in two formats, continuous “monolithic” blocks, and beads. Optimization of the preparation process and hypercrosslinking conditions enabled generation of microporous beads and monoliths with a pore volume of 0.70–0.78 cm3/g and a pore size of around 0.63 nm. The total gravimetric uptake of methane calculated from adsorption isotherms was 0.156 g/g at 65 bar and 273 K and represented a volumetric uptake of 164 cm3 CH4 (STP) per 1 cm3 of the sorbent. While the total gravimetric uptake of methane using beads is similar to that of monolith, their volumetric storage capacity is only 82.7 cm3 (STP) per 1 cm3 at 65 bar and 273 K due to the inevitable presence of void volumes between the particles. Therefore, the novel continuous “monolithic” format of the hypercrosslinked polymer was found more advantageous since the monolith can fill the available volume of the container completely and exhibit a volumetric storage capacity that is twice as large as that found for the hypercrosslinked beads. The isosteric heat of CH4 adsorption by both monolith and beads was 14.5 kJ/mol and 15.0 kJ/mol, respectively, which is large enough to adsorb methane at room temperature. The hypercrosslinked monolith could be reused and did not lose its storage capacity even after twenty cycles of repeated use.

A new thermally switchable molecularly imprinted monolith for the selective capture and release of proteins has been designed. First, a generic poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith reacted with ethylenediamine followed by functionalization with 2-bromoisobutyryl bromide to introduce the initiator for atom transfer radical polymerization. Subsequently, a protein-imprinted poly(N-isopropylacrylamide) layer was grafted onto the surface of the monolithic matrix by atom transfer radical polymerization. Scanning electron microscopy and energy-dispersive X-ray spectroscopy of the cross-sections of imprinted monoliths confirmed the formation of dense poly(N-isopropylacrylamide) brushes on the pore surface. The imprinted monolith exhibited high specificity and selectivity toward its template protein myoglobin over competing proteins and a remarkably large maximum adsorption capacity of 1641 mg/g. Moreover, this "smart" imprinted monolith featured thermally responsive characteristics that enabled selective capture and easy release of proteins triggered only by change in temperature with water as the mobile phase and avoided use of stronger organic solvents or change in ionic strength and pH.

Metal-organic frameworks are a new category of advanced porous materials with large surface areas and porosities, uniform pore sizes, tunable surface chemistry, and structural diversity. In combination with monoliths, they allow the fine tuning of desired interactions required in a variety of applications. This review article summarizes results of recent studies focused on synthetic strategies enabling incorporation of metal-organic frameworks in monolithic structures. A diverse array of applications including chromatographic separation, solid-phase microextraction, sample enrichment, heterogeneous catalysis, and enzymatic catalysis are also described.

Thermal energy storage (TES) transfers heat to storage media during the charging period, and releases it at a later stage during the discharging step. It can be usefully applied in solar plants, or in industrial processes, such as metallurgical transformations. Sensible, latent and thermo-chemical media store heat in materials which change temperature, phase or chemical composition, respectively. Sensible heat storage is well-documented. Latent heat storage, using phase change materials (PCMs), mainly using liquid–solid transition to store latent heat, allows a more compact, efficient and therefore economical system to operate. Thermo-chemical heat storage (TCS) is still at an early stage of laboratory and pilot research despite its attractive application for long term energy storage. The present review will assess previous research, while also adding novel treatments of the subject. TES systems are of growing importance within the energy awareness: TES can reduce the LCOE (levelized cost of electricity) of renewable energy processes, with the temperature of the storage medium being the most important parameter. Sensible heat storage is well-documented in literature and applied at large scale, hence limited in the content of the present review paper. Latent heat storage using PCMs is dealt with, specifically towards high temperature applications, where inorganic substances offer a high potential. Finally, the use of energy storage through reversible chemical reactions (thermo-chemical storage, TCS) is assessed. Since PCM and TCS storage media need to be contained in a capsule (sphere, tube, sandwich plates) of appropriate materials, potential containment materials are examined. A heat transfer fluid (HTF) is required to convey the heat from capture, to storage and ultimate re-use. Particle suspensions offer a valid alternative to common HTF, and a preliminary assessment confirms the advantages of the upflow bubbling fluidized bed and demonstrates that particulate suspensions enable major savings in investment and operating costs. Novel treatments of the TES subject in the review involve the required encapsulation of the latent and chemical storage media, the novel development of powder circulation loops as heat transfer media, the conductivity enhancement of PCMs, the use of lithium salts, among others.

A reusable carrier for enzyme immobilization consisting of magnetic Fe 3 O 4 nanoparticles coated with a layer of gold nanoparticles (AuNPs) has been demonstrated. The gold nanoparticles served as an intermediate ligand on which trypsin was reversibly immobilized. This immobilized trypsin reactor was used for the digestion of standard proteins that was achieved within 15 min. After digestion, the trypsin-loaded nanoparticles were recovered from the reaction mixture using a magnet. The peptides in digest were then determined using HPLC and MALDI-TOF mass spectrometry. Sequence coverages of 93.8%, 90.9%, and 54.1% were observed for myoglobin, cytochrome c, and bovine serum albumin, respectively. Our newly designed AuNP@Fe 3 O 4 enzymatic nanosystem enabled significant acceleration of the enzyme catalyzed reaction. We also observed a higher efficiency compared with in-solution digestion using free trypsin, and with reactors produced using conventional immobilization techniques such as electrostatic interaction, covalent bonding, and formation of metal chelate complexes. Furthermore, the use of gold nanoparticles as the intermediate ligand enabled regeneration of the enzyme and recovery of the activity in our system simply by stripping the inactive trypsin from the gold nanoparticles using sodium borohydride followed by the immobilization of fresh trypsin.

Molecularly imprinted polymers (MIPs) emerged half a century ago have now attracted tremendous attention as artificial receptors or plastic antibodies. Although the preparation of MIPs targeting small molecules, peptides, or even proteins is straightforward and well-developed, the molecular imprinting of microorganisms still remains a big challenge. This review highlights the preparation of MIPs that reveal biomimetic specificity and selectivity towards microorganisms by creating the well-defined cell recognition sites. We present the state-of-the-art strategies for the expeditious synthesis of MIPs targeting microorganism including surface components imprinting, cell mediated lithography, and microcontact stamping. These receptor-like biomimetic materials have garnered increasing attention in different fields. In this review, we also describe the diverse applications of microorganism-imprinted polymers such as microbial activation, microbial fuel cells, and microorganism detection and sensing. The major challenges and further prospects on the design of microorganism-imprinted polymers is also outlined.

Agar microspheres were prepared by water-oil emulsification and cross-linked under alkaline condition. The thermoresponsive hydrophobic copolymer, poly(N-isopropylacrylamide-co-lauryl methacrylate-co-acrylamide), was grafted on the agar microspheres via atom transfer radical polymerization. The agar microspheres grafted with copolymers were characterized by light microphotography, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The chain lengths and hydrophobic monomer ratio of the grafting linear polymer had significant effects on the hydrophobicity and adsorption capacity of agar microspheres at different temperatures. The thermoresponsive microspheres were used for separation of proteins and showed binding and release behavior by change of temperatures without change in mobile phase composition. Thus, we suggest thermoresponsive agar microspheres as an alternative separation media for all-aqueous bioseparations.

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.

Fabrication of metal-organic frameworks (MOFs) with large apertures triggers a brand-new research area for selective encapsulation of biomolecules within MOF nanopores. The underlying inclusion mechanism is yet to be clarified however. Here we report a molecular dynamics study on the mechanism of protein encapsulation in MOFs. Evaluation for the binding of amino acid side chain analogues reveals that van der Waals interaction is the main driving force for the binding and that guest size acts as a key factor predicting protein binding with MOFs. Analysis on the conformation and thermodynamic stability of the miniprotein Trp-cage encapsulated in a series of MOFs with varying pore apertures and surface chemistries indicates that protein encapsulation can be achieved via maintaining a polar/nonpolar balance in the MOF surface through tunable modification of organic linkers and Mg-O chelating moieties. Such modifications endow MOFs with a more biocompatible confinement. This work provides guidelines for selective inclusion of biomolecules within MOFs and facilitates MOF functions as a new class of host materials and molecular chaperones.

Matching the power supply with demand is a key issue for the development of renewable energy sources: the intermittence of wind or solar power can be overcome by integrating an energy storage system. In comparison with sensible and latent heat storage, thermochemical heat storage has the advantages of both a high energy density, so that reaction products can be stored at ambient temperature for later reuse, and a flexibility of transportation when off-site use is required. An initial thermodynamic and kinetic screening of thermochemical reactions in the temperature range of about 600 to 1200 K is presented. Thermodynamics and kinetics are used to characterize the reactions through the equilibrium temperature, the heat of reaction, the reaction rates, and recovery work. These aspects were studied theoretically and experimentally. The analysis defines the essential design parameters and provides guidance for the important assessment criteria of new candidate reaction systems.

Bio-ethanol, as a clean and renewable fuel, is gaining increasing attention, mostly through its major environmental benefits. It can be produced from different kinds of renewable feedstock such as e.g. sugar cane, corn, wheat, cassava (first generation), cellulose biomass (second generation) and algal biomass (third generation). The conversion pathways for the production of bio-ethanol from disaccharides, from starches, and from lignocellulosic biomass are examined. The common processing routes are described, with their mass and energy balances, and assessed by comparing field data and simulations. Improvements through 5 possible interventions are discussed, being (i) an integrated energy-pinch of condensers and reboilers in the bio-ethanol distillation train; (ii) the use of Very High Gravity (VHG) fermentation; (iii) the current development of hybrid processes using pervaporation membranes; (iv) the substitution of current ethanol dewatering processes to >99.5 wt% pure ethanol by membrane technology; and (v) additional developments to improve the plant operation such as the use of microfiltration of the fermenter broth to protect heat exchangers and distillation columns against fouling, or novel distillation concepts. Whereas the benefits of introducing these techniques are recognized, extensive research is still needed to scientifically and economically justify their application. The paper finally presents a tentative economic assessment, with production costs not only depending on the extent of applying process improvements, but also on the raw material used in the process.

Commercially available silica-based monolithic columns Chromolith RP-8e, Chromolith RP-18, and Chromolith HR RP-18, and polymer-based monolithic columns ProSwift RP-1S, ProSwift RP-2H, and ProSwift RP-3U varying in pore size and bonded phase have been tested for the fast separation of selected sets of analytes. These mixtures of analytes included small molecules (uracil, caffeine, 1-phenylethanol, butyl paraben, and anthracene), acylated insulins, and intact proteins (ribonuclease A, cytochrome C, transferrin, apomyoglobin, and thyroglobulin), and covered wide range of chemistries and sizes. Small molecules were well separated with a height equivalent to theoretical plate of 11-26 μm using silica-based monolithic columns, while organic polymer-based monoliths excelled in the fast sub 1 min baseline separations of large molecules. A peak capacity of 37 was found for separation of acylated insulins on Chromolith columns using a 3 min gradient at a flow rate of 3 ml/min. Poor recovery of proteins from Chromolith columns and significant peak tailing of small molecules using ProSwift columns were the major obstacles in using monolithic columns in those applications.

Glycosaminoglycans (GAGs) are unbranched polyanionic polysaccharides involved in a wide spectrum of biological activities. Accumulation and/or structural alteration of GAGs in biological samples have been found correlated with diseases, making these molecules potential biomarkers for the diagnosis of these diseases and monitoring treatment effects. Detection and structural characterization of GAGs in biological samples have been challenging mainly due to their low abundance, structural complexity and heterogeneity. It is highly demanding to develop robust and reliable methodologies for structural characterization and quantification of GAGs, not only for research purposes, but most importantly for pharmaceutical and potential clinical applications, including pharmacokinetic studies for GAGs based drugs and identification of novel biomarkers. In this review, we have collected currently available techniques for detection and analysis of GAGs in biological samples, advantages and drawbacks of these techniques are discussed. Specially, perspectives of the developing methods for GAGs are reviewed.

Simple devices for the adsorption and preconcentration of metal ions comprising various monolithic polymers have been prepared by in situ polymerization within the 5.5 cm long and 5.6 mm i.d. polypropylene syringes. Poly(glycidyl methacrylate- co -ethylene dimethacrylate) monolith was modified with ethylenediamine to obtain the chelating material. The poly(butyl methacrylate- co -ethylene dimethacrylate) and poly(lauryl methacrylate- co -ethylene dimethacrylate) monoliths were first photografted with glycidyl methacrylate prior to functionalization with ethylenediamine. Alternatively, other chelating functionalities including poly(ethylene imines) varying in molecular weight and shape (linear and branched) as well as lysozyme were also attached to the monolithic supports. We found that the poly(glycidyl methacrylate- co -ethylene dimethacrylate) monolith functionalized with ethylenediamine exhibited the best chelating properties characterized with rapid adsorption and a capacity of 111.2 mg/g (537 μmol/g) for Pb 2+ , 38.1 mg/g (649 μmol/g) for Ni 2+ , 69.9 mg/g (1100 μmol/g) for Cu 2+ , and 188.9 mg/g (3633 μmol/g) for Cr 3+ . The very fast desorption was then achieved using 1.0 mol/L HNO 3 as the eluent. An enrichment factor of 300 was observed for metal ions adsorbed from solutions containing 2 ppb of the metal.

Dimerization of cyclodextrin (CD) molecules is an elementary step in the construction of CD-based nanostructured materials. Cooperative binding of CD cavities to guest molecules facilitates the dimerization process and, consequently, the overall stability and assembly of CD nanostructures. In the present study, all three dimerization modes (head-to-head, head-to-tail, and tail-to-tail) of β-CD molecules and their binding to three isoflavone drug analogues (puerarin, daidzin, and daidzein) were investigated in explicit water surrounding using molecular dynamics simulations. Total and individual contributions from the binding partners and solvent environment to the thermodynamics of these binding reactions are quantified in detail using free energy calculations. Cooperative drug binding to two CD cavities gives an enhanced binding strength for daidzin and daidzein, whereas for puerarin no obvious enhancement is observed. Head-to-head dimerization yields the most stable complexes for inclusion of the tested isoflavones (templates) and may be a promising building block for construction of template-stabilized CD nanostructures. Compared to the case of CD monomers, the desolvation of CD dimers and entropy changes upon complexation prove to be influential factors of cooperative binding. Our results shed light on key points of the design of CD-based supramolecular assemblies. We also show that structure-based calculation of binding thermodynamics can quantify stabilization caused by cooperative effects in building blocks of nanostructured materials.

Encapsulation of enzymes in metal-organic frameworks (MOFs) is often obstructed by the small size of the orifices typical of most reported MOFs, which prevent the passage of larger-size enzymes. Here, the preparation of hierarchical micro- and mesoporous Zn-based MOFs via the templated emulsification method using hydrogels as a template is presented. Zinc-based hydrogels featuring a 3D interconnecting network are first produced via the formation of hydrogen bonds between melamine and salicylic acid in which zinc ions are well distributed. Further coordination with organic linkers followed by the removal of the hydrogel template produces hierarchical Zn-based MOFs containing both micropores and mesopores. These new MOFs are used for the encapsulation of glucose oxidase and horseradish peroxidase to prove the concept. The immobilized enzymes exhibit a remarkably enhanced increased operational stability and enzymatic activity with a kcat /km value of 85.68 mm s-1 . This value is 7.7-fold higher compared to that found for the free enzymes in solution, and 2.7-fold higher than enzymes adsorbed on conventional microporous MOFs. The much higher catalytic activity of the mesoporous conjugate for Knoevenagel reactions is demonstrated, since the large pores enable easier access to the active sites, and compared with that observed for catalysis using microporous MOFs.

A new enzymatic glucose biosensor based on reversible co-immobilization of horseradish peroxidase (HRP) and glucose oxidase (GOx) on a pH-responsive imprinted monolith is prepared. The poly(4-vinylphenylboronic acid)-grafted imprinted polymer using HRP as a template is formed via surface initiated atom transfer radical polymerization within the pores of brominated poly(glycidyl methacrylate-co-ethylene dimethacrylate) macroporous monolith contained in a 100 μm I.D. capillary column. The two enzymes conjugate is formed via the strong affinity interaction between biotin-labeled GOx and streptavidin-labeled HRP. The modulation of the external pH value enables reusability of the biosensor simply using stripping of the inactive enzymes at a low pH value and subsequent immobilization of fresh enzymes at a high pH value. Under the optimized conditions, the enzymatic biosensor features excellent performance in detection of glucose with a linear range of its concentration from 0.11 to 38.85 mmol/L and a limit of detection of 0.03 mmol/L. A relative standard deviation of 3.7% is calculated from determination of twenty glucose samples. This novel enzymatic sensing system is successfully applied for determination of glucose in human serum, and confirms an enhancement both in selectivity and specificity compared to the more traditionally clinical methods.

pH-responsive surface layers consisting of porous polymer monoliths containing thiol groups have been prepared via a "thiol-ene" click reaction using a mixture of hydrophobic and ionizable unsaturated "ene" compounds. A proportion of these two "ene" reagents controlled the wettability of the surface that varied with pH, and enabled reversible switching between superhydrophilic and superhydrophobic properties.

Porcine lipase has been reversibly immobilized on a monolithic polymer support containing thiol functionalities prepared within confines of a fused silica capillary and functionalized with gold nanoparticles. Use of gold nanoparticles enabled rejuvenation of the activity of the deactivated reactor simply by stripping the inactive enzyme from the nanoparticles using 2-mercaptoethanol and subsequent immobilization of fresh lipase. This flow through enzymatic reactor was then used to catalyze the hydrolysis of glyceryl tributyrate (tributyrin). The highest activity was found within a temperature range of 37–40°C. The reaction kinetics is characterized by Michaelis–Menten constant, Km = 10.9 mmol/L, and maximum reaction rate, Vmax = 5.0 mmol/L min. The maximum reaction rate for the immobilized enzyme is 1,000 times faster compared to lipase in solution. The fast reaction rate enabled to achieve 86.7% conversion of tributyrin in mere 2.5 min and an almost complete conversion in 10 min. The reactor lost only less than 10% of its activity even after continuous pumping through it a solution of substrate equaling 1,760 reactor volumes. Finally, potential application of this enzymatic reactor was demonstrated with the transesterification of triacylglycerides from kitchen oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. Biotechnol. Bioeng. 2014;111: 50–58. © 2013 Wiley Periodicals, Inc.