The real-time monitoring of specific analytes in situ in the living body would greatly advance our understanding of physiology and the development of personalized medicine. Because they are continuous (wash-free and reagentless) and are able to work in complex media (e.g., undiluted serum), electrochemical aptamer-based (E-AB) sensors are promising candidates to fill this role. E-AB sensors suffer, however, from often-severe baseline drift when deployed in undiluted whole blood either in vitro or in vivo. We demonstrate that cell-membrane-mimicking phosphatidylcholine (PC)-terminated monolayers improve the performance of E-AB sensors, reducing the baseline drift from around 70% to just a few percent after several hours in flowing whole blood in vitro. With this improvement comes the ability to deploy E-AB sensors directly in situ in the veins of live animals, achieving micromolar precision over many hours without the use of physical barriers or active drift-correction algorithms.

Three-dimensional (3D) covalent organic frameworks (COFs) are excellent porous crystalline polymers for numerous applications, but their building units and topological nets have been limited. Herein we report the first 3D large-pore COF with stp topology constructed with a 6-connected triptycene-based monomer. The new COF (termed JUC-564) has high surface area (up to 3300 m 2 g -1 ), the largest pore (43 Å) among 3D COFs, and record-breaking low density in crystalline materials (0.108 g cm -3 ). The large pore size of JUC-564 is confirmed by the incorporation of a large protein. This study expands the structural varieties of 3D COFs as well as their applications for adsorption and separation of large biological molecules. Supporting InformationMethods and synthetic procedures, SEM, FTIR, solid state 13 C NMR, TGA, BET plot, and unit cell parameters. This material is available free of charge via the internet at http://pubs.acs.org.

Lignin-based polyurethane elastomers (LPUe) with high stiffness, strength, and toughness were facilely prepared by direct cross-linking of unfunctionized lignin as hard segments and poly­(propylene glycol) tolylene 2,4-diisocyanate terminated (PPGTDI) as soft domains. The effects of lignin molecular weight (3600 and 600 g mol–1) and weight fraction (5–40 wt %) on the thermal and mechanical properties of LPUe were studied. With an increase in lignin content, LPUe exhibited improved thermal stability, and the glass transition temperature (T g) also increased, especially for LPUe derived from lignin with low lignin molecular weight of 600 g mol–1 (600-LPUe). Furthermore, LPUe also exhibits excellent mechanical properties. For 600-LPUe with 40 wt % of lignin, the Young’s modulus, tensile strength, and strain at break reach 176.4 MPa, 33.0 MPa, and 1394%, respectively, which could be attributed to better dispersion of low molecular weight lignin in elastomers as evident from DSC, SEM, and TEM studies. Our results demonstrate the potential application of unmodified lignin in developing biobased high-performance PU materials. This is in contrast to many current studies of LPUe systems that need lignin modification to prepare PU materials.

Summary The value of polymers is manifested in their vital use as building blocks in material and life sciences. Ribonucleic acid (RNA) is a polynucleic acid, but its polymeric nature in materials and technological applications is often overlooked due to an impression that RNA is seemingly unstable. Recent findings that certain modifications can make RNA resistant to RNase degradation while retaining its authentic folding property and biological function, and the discovery of ultra-thermostable RNA motifs have adequately addressed the concerns of RNA unstability. RNA can serve as a unique polymeric material to build varieties of nanostructures including nanoparticles, polygons, arrays, bundles, membrane, and microsponges that have potential applications in biomedical and material sciences. Since 2005, more than a thousand publications on RNA nanostructures have been published in diverse fields, indicating a remarkable increase of interest in the emerging field of RNA nanotechnology. In this review, we aim to: delineate the physical and chemical properties of polymers that can be applied to RNA; introduce the unique properties of RNA as a polymer; review the current methods for the construction of RNA nanostructures; describe its applications in material, biomedical and computer sciences; and, discuss the challenges and future prospects in this field.

Lithium-ion batteries (LIBs) have profoundly affected most aspects of human's society in recent years. [1] With wide applications of smarter electronics and electric vehicles, the fast charging/discharging capability and safety issues became the key challenges for further commercialization of LIBs. [2] However, this requirement might be hardly satisfied if the anode were still graphite-based materials, because of the safety issues of short circuits caused by lithium dendrite formation at high charge rates when near the working potential of graphite (only 0.2 V higher than Li + /Li). [3] Although insertion-type Li 4 Ti 5 O 12 (LTO) anode has an outstanding high-rate performance and a safety working potential at about 1.55 V (vs Li + /Li), it exhibits a rather low theoretical specific capacity of 175 mAh g −1 , which would severely limit the energy density of batteries. [4] Recently, the conversion and alloying anode materials with high specific capacities have been reported to promote their rate performance via introducing nano or porous structures to shorten diffusion distances. However, they still face many problems such as huge volume changes, electrolyte decomposition, low initial Coulombic efficiency and limited cycling life. [5] Notably, nano or porous materials usually exhibit enhanced rate performance but are not preferred by industry for the intrinsic shortage of volumetric energy density. [6] Thus, it is essential to explore anode materials combined with high rate performance, satisfying capacity and safety.Recently, niobium pentoxide (Nb 2 O 5 ) has drawn wide attentions and is expected as a suitable alternative anode material for its ultrafast Li storage kinetics, promising capacity and safe operating potential. [7] The Nb 2 O 5 owns various configurations under different preparation conditions, which are denoted by letters TT, T, B, M, and H. [8] Among these crystals, the T-type Nb 2 O 5 (T-Nb 2 O 5 ) has received the highest attention because it shows little structural change on intercalation (no phase transition) and high-rate behavior so called as an "intercalation pseudocapacitance" material. [9] However, its specific capacity is still below 200 mAh g −1 (1.0-3.0 V vs Li + /Li). [10] In contrast, H-type Nb 2 O 5 (H-Nb 2 O 5 ) owns specific capacity of as high as over 250 mAh g −1 (1.0-3.0 V versus Li + /Li) and a flat charge/discharge Exploring anode materials with fast, safe, and stable Li-(de)intercalation is of great significance for developing next-generation lithium-ion batteries. Monoclinic H-type niobium pentoxide possesses outstanding intrinsic fast Li-(de) intercalation kinetics, high specific capacity, and safety; however, its practical rate capability and cycling stability are still limited, ascribed to the asynchronism of phase change throughout the crystals. Herein this problem is addressed by homogenizing the electron and Li-ion conductivity surrounding the crystals. An amorphous N-doped carbon layer is introduced on the micrometer single-crystal H-Nb 2 O 5 particle to optimize...

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