Microperoxidase-11 has for the first time been successfully immobilized into a mesoporous metal-organic framework (MOF) consisting of nanoscopic cages and it demonstrates superior enzymatic catalysis performances compared to its mesoporous silica counterpart.

conventional 3D and 2D types when used for miniaturized electronic devices, textile electronics, and implantable medical devices. [1,2] However, compared with other energy storage devices such as batteries, the much lower stored specific energy of 1D supercapacitors limited their practical applications. Since the energy stored in a supercapacitor is proportional to CV 2 (E = 1/2 CV 2 , where C is the capacitance of the device and V is the operating voltage), enhancements in energy density can be achieved by increasing the specific capacitance (C) or widening the operating voltage range (V). [3] Specific capacitance can be improved by the incorporation of electrochemically active nanomaterials (e.g., metal oxides or conducting polymers) into the base electrode materials, such as carbon nanotube (CNT) or graphene assemblies. In comparison, insufficient attention has been paid to improve the voltage range of flexible supercapacitors. This is especially true in fiber-shaped supercapacitors (FSSs), which usually show ideal capacitive behavior only in a relatively small potential window (0.8-1.0 V), [4][5][6][7][8][9][10][11][12][13][14] and consequently deliver limited energy or power densities. An effective approach for addressing this issue is the strategy of asymmetric electrode configuration by coupling different positive and negative electrode materials with well-separated potential windows for achieving a high operating voltage. [15][16][17][18] So far, several papers addressing asymmetric FSS can be found in the literature. A fiber-based flexible all-solid state asymmetric supercapacitor using molybdenum disulfide (MoS 2 )-reduced graphene oxide (rGO)/multiwalled carbon nanotube (MWCNT) and rGO/MWCNT fibers has accomplished a potential window of 1.4 V with high Coulombic efficiency and improved energy density. [19] Cheng et al. reported an asymmetric fiber-shaped supercapacitor based on MnO 2 /conducting polymer/CNT fiber and ordered microporous carbon/ CNT hybrid fiber as positive and negative electrode, respectively, which produced a high energy density of 11.3 mW h cm −3 . [20] Yang et al. fabricated a fiber-shaped asymmetric supercapacitor by using porous NiO/Ni(OH) 2 /PEDOT/contra wire electrode as the positive electrode, and the ordered mesoporous carbon fiber as the negative electrode. The supercapacitor exhibited an output voltage of 1.5 V. [21] Wang et al. used titanium wire/cobalt oxide (Co 3 O 4 ) nanowires and carbon fibers/graphene electrodes to fabricate an asymmetric supercapacitor, which enhanced both stored energy and delivered power by at least 1860% compared with that of the supercapacitor with a potential window The emerging fiber-shaped supercapacitors (FSSs) have motivated tremendous research interest in energy storage devices. However, challenges still exist in the pursuit of combination of excellent electrochemical performance and mechanical stretchability. Here, a core-sheath asymmetric FSS is first made by wrapping gel electrolyte coated carbon nanotube (CNT)@MnO 2 core fiber with CNT@...

The emergence of stretchable electronic devices has attracted intensive attention. However, most of the existing stretchable electronic devices can generally be stretched only in one specific direction and show limited specific capacitance and energy density. Here, we report a stretchable isotropic buckled carbon nanotube (CNT) film, which is used as electrodes for supercapacitors with low sheet resistance, high omnidirectional stretchability, and electro-mechanical stability under repeated stretching. After acid treatment of the CNT film followed by electrochemical deposition of polyaniline (PANI), the resulting isotropic buckled acid treated CNT@PANI electrode exhibits high specific capacitance of 1147.12 mF cm(-2) at 10 mV s(-1). The supercapacitor possesses high energy density from 31.56 to 50.98 μWh cm(-2) and corresponding power density changing from 2.294 to 28.404 mW cm(-2) at the scan rate from 10 to 200 mV s(-1). Also, the supercapacitor can sustain an omnidirectional strain of 200%, which is twice the maximum strain of biaxially stretchable supercapacitors based on CNT assemblies reported in the literature. Moreover, the capacitive performance is even enhanced to 1160.43-1230.61 mF cm(-2) during uniaxial, biaxial, and omnidirectional elongations.

No abstract

An unprecedented nanoscopic polyhedral cage-containing metal-metalloporphyrin framework, MMPF-1, has been constructed from a custom-designed porphyrin ligand, 5,15-bis(3,5-dicarboxyphenyl)porphine, that links Cu(2)(carboxylate)(4) moieties. A high density of 16 open copper sites confined within a nanoscopic polyhedral cage has been achieved, and the packing of the porphyrin cages via an "ABAB" pattern affords MMPF-1 ultramicropores which render it selective toward adsorption of H(2) and O(2) over N(2), and CO(2) over CH(4).

A major driving force behind the recent surge of interest in metal-organic frameworks (MOFs) [1] lies with their amenability to design using crystal engineering [2a-d] strategies. In particular, MOFs with specific composition and topology can be targeted by judicious selection of organic linkers and metal-based molecular building blocks [2e-g] (MBBs) that serve as nodes. [2] Furthermore, their modular nature means that prototypal MOFs can serve as blueprints or platforms for a plethora of derivatives with controlled pore size and surface area, as exemplified by the practice of "reticular synthesis". [3] Such features make MOFs stand out over traditional porous materials, and afford them with potential for use in gas storage, [4] separation, [5] CO 2 capture, [6] sensor, [7] catalysis, [8] and other areas. [9] High-symmetry MOFs based upon high-connectivity polyhedral cage MBBs that are in effect supermolecular building blocks (SBBs) can provide exquisite control over structure because of their high connectivity and also afford the features of confined nanospace [10] and extra-large surface area. [11] Such MOFs have afforded superior performance in the context of gas storage for hydrogen, methane, CO 2 , and other gas molecules. [4, 6, 11,12] The nature of the nanospace in SBB-based MOFs is such that they can encapsulate catalytically active species, for example, organometallics, [13] polyoxometallates, [14] metalloporphyrins (porph@MOMs), [15] and enzymes. [16] Along with encapsulation of catalysts, it is possible to generate porphyrin-walled MOFs by customdesigning metalloporphyrin moieties so that they can serve as vertices and/or edges and/or faces. In principle, the metal

A novel one-step electrochemical synthesis of the reduced graphene oxide and poly(m-aminobenzenesulfonic acid, ABSA) nanocomposite (PABSA-rGNO) via pulse potentiostatic method (PPM) for direct and freely switchable detection of target genes is presented. Unlike most electrochemical preparation of hybrids based on rGNO and polymer, electrochemical synthesis of PABSA (during the pulse electropolymerization period of PPM) and electrochemical reduction of rGNO (during the resting period of PPM), in this paper, were alternately performed. The total progress synchronously resulted in PABSA-rGNO nanocomposite. This nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The PABSA-rGNO nanocomposite integrated graphene (a single-atom thick, two-dimensional sheet of sp(2) bonded conjugated carbon) with PABSA (owning rich-conjugated structures, functional groups, and excellent electrochemical activity), which could serve as an ideal electrode material for biosensing and electrochemical cell, etc. As an example, the immobilization of the specific probe DNA was successfully conducted via the noncovalent method due to the π-π* interaction between conjugated nanocomposite and DNA bases. The hybridization between the probe DNA and target DNA induced the product dsDNA to be released from conjugated nanocomposite, accompanied with the self-signal regeneration of nanocomposite ("signal-on"). The self-signal changes served as a powerful tool for direct and freely switchable detection of different target genes, and the synergistic effect of PABSA-rGNO nanocomposite effectively improved the sensitivity for the target DNA detection.

Expanding the application range of flame-retardant polymer biocomposites remains a huge challenge for a sustainable society. Despite largely enhanced flame retardancy, until now the resultant poly(lactic acid) (PLA) composites still suffer reduced tensile strength and impact toughness due to improper material design strategies. We, herein, demonstrate the design of a green flame retardant additive (ammonium polyphosphate (APP)@cellulose nanofiber (CNF)) via using the cellulose nanofibers (CNFs) as the green multifunctional additives hybridized with ammonium polyphosphate (APP). The results show that PLA composite with 5 wt % loading of APP@CNF can pass the UL-94 V-0 rating, besides a high limited oxygen index of 27.5%, indicative of a significantly enhanced flame retardancy. Moreover, the 5 wt % of APP@CNF enables the impact strength (σ i ) of the PVA matrix to significantly improve from 7.63 to 11.8 kJ/m 2 (increase by 54%), in addition to a high tensile strength of 50.3 MPa for the resultant flame-retardant PLA composite. The enhanced flame retardancy and mechanical strength performances are attributed to the improved dispersion of APP@CNF and its smaller phase size within the PLA matrix along with their synergistic effect between APP and CNF. This work opens up a facile innovative methodology for the design of high-performance ecofriendly flame retardants and their advanced polymeric composites.