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Electrochemical sensing performance is often compromised by electrode biofouling (e.g. proteins nonspecific binding) in complex biological fluids; however, the design and construction of a robust biointerface remains a great challenge. Herein, inspired by nature, we demonstrate a robust polydopamine‐engineered biointerfacing, to tailing zwitterionic molecules (i.e. sulfobetaine methacrylate, SBMA) through Michael Addition. The SBMA‐PDA biointerface can resist proteins nonspecific binding in complex biological fluids while enhancing interfacial electron transfer and electrochemical stability of the electrode. In addition, this sensing interface can be integrated with tissue‐implantable electrode for in vivo analysis with improved sensing performance, preserving ca. 92.0% of the initial sensitivity after 2 h of implantation in brain tissue, showing low acute neuroinflammatory responses and good stability both in normal and in Parkinson′s disease (PD) rat brain tissue. [ABSTRACT FROM AUTHOR]

It is of interest to in vivo monitor the co-dynamics of different substances. However, the tracking of multiple species is still challenging. In this work, we demonstrate an in vivo electrochemical method by using multi-potential step amperometry to in vivo detect ascorbic acid (AA) and oxygen (O2) simultaneously. In order to achieve good selectivity and high sensitivity for both AA and O2, we design a cobalt corrole [Co(tpfc)(py)2] (tpfc = 5,10,15-tris(penta-fluorophenyl) corrole, py = pyridine, denoted as Co-TPFC) and carbon nanotube nanocomposite to modify a carbon fiber microelectrode (Co-TPFC/MWNT/CFE). This Co-TPFC/MWNT/CFE exhibits excellent electrocatalytic properties towards the reduction of O2 preceding a 4e process and facilitates the oxidation of AA at low potential in the physiological environment. Based on this, we realize simultaneous detection of AA and O2 using two-potential steps (one cathodic (−0.2 V) and the other anodic (+0.05 V)) with 1 second step time. Both in vitro and in vivo experiments proved the feasibility of this method. This demonstrated strategy is useful for us to understand various physiological and pathological processes associated with O2 and AA co-dynamics, and also provides an idea for detecting multiple substances simultaneously. [ABSTRACT FROM AUTHOR]

Aiming to investigate the mix design of eco-friendly UHPC with supplementary cementitious materials and coarser aggregates, we comprehensively studied the workability, microstructure, porosity, compressive strength, flexural strength, and Young's modulus of UHPC. Relationship between compressive strength and Young's modulus was obtained eventually. It is found that the compressive strength, flexural strength, and Young's modulus of UHPC increase by 19.01%, 10.81%, and 5.99%, respectively, when 40wt% cement is replaced with supplementary cementitious materials. The relationship between compressive strength and Young's modulus of UHPC is an exponential form. [ABSTRACT FROM AUTHOR]

Nanoskiving, benefiting from its simple operation and high reproducibility, is a promising method to fabricate nanometer-size electrodes. In this work, we report the fabrication of Au nanowire electrodes with different shapes and well-controlled sizes through nanoskiving. Au nanowire block electrodes, membrane electrodes and tip electrodes are prepared with good reproducibility. Steady-state cyclic voltammograms (CVs) demonstrate that all these electrodes behave well as nanoband ultramicroelectrodes. A fast heterogeneous electron transfer rate constant can be extracted reliably from steady-state CVs at various size Au nanowire block electrodes by the Koutecký–Levich (K–L) method. The Au nanowire membrane electrodes demonstrate good sensitivity toward the oxidation of catecholamine and could monitor catecholamine released from rat adrenal chromaffin cells stimulated by high K+. [ABSTRACT FROM AUTHOR]

Abstract Currently, researchers have been studying ways to reduce the raw materials costs and energy consumption of ultra-high-performance concrete (UHPC) production. Therefore, the feasibility of using aeolian sand to partially or totally replace natural river sand in UHPC is studied. The workability and quasi-static and dynamic mechanical properties were comprehensively studied to investigate the effect of aeolian sand on UHPCs. It was found that: 1) The workability of UHPCs was significantly improved when river sand was partially or totally replaced by aeolian sand; 2) The compressive strength of UHPCs could be enhanced when river sand was partially or totally replaced by aeolian sand, and the differences in flexural strength among all the mixtures were not distinct; 3) Incorporation of aeolian sand as a fine aggregate slightly increased the toughness of UHPCs under uniaxial compression test; 4) The differences in the dynamic impact parameters among UHPCs containing aeolian or river sand, as well as those in the parameter evolution rules regarding impact times, were not obvious. The findings of this research promote the preparation of eco-friendly UHPC and provide a new way to use waste resources. [ABSTRACT FROM AUTHOR]

A mixed-ion strategy to achieve carbon nanotube-decorated Co/N-doped hollow carbon hybrids (CNTs-Co/NHC) is developed by precisely controlling the Co2+/Zn2+ molar ratio in the ZIFs-CoxZn1−x precursor. The optimized CNTs-Co/NHC-0.23 catalyst shows outstanding catalytic activity and durability for the oxygen reduction reaction (ORR) and outperformed commercial Pt/C. [ABSTRACT FROM AUTHOR]

Abstract: The rational construction of highly active and stable non‐noble metal electrocatalysts for the oxygen reduction reaction (ORR) is an ongoing challenge for practical applications of catalysts. Here, we report a novel nanostructured hollow N‐doped carbon hybrid through pyrolysis of silica@CoZn‐coordinated zeolitic imidazolate frameworks. The carbon layer encased cobalt nanoparticles were embedded in the hierarchically porous carbon catalyst (Co@C‐HN‐hC). Profiting from the synergistic effect between highly active Co@C NPs and HN‐hC, the Co@C‐HN‐hC catalyst exhibited remarkable catalytic performances as compared to porous N‐doped hollow carbon (N‐hC) and N‐doped carbon encased Co NPs (Co@N‐C). The electrochemical measurements show that the performances of the Co@C‐HN‐hC catalyst is close to that of the Pt/C catalysts, along with an excellent stability and durability in the ORR process. This study provides a guideline for controllable design of carbon‐based ORR catalysts for substituting noble metal catalysts. [ABSTRACT FROM AUTHOR]

An efficient electrochemical immunosensor can offer the potential for the detection of protein cancer biomarkers due to its high sensitivity, low cost and possible integration in compact analytical devices. In the last several years, researchers have developed various electrochemical immunoassay methods for the detection of protein cancer biomarkers. Significant progresses have been made in the study of electrochemical immunosensor that based on CNTs, especially in the fields of clinical screening and diagnosis of cancer field. This is because CNTs possess unique structural, mechanical and electronic properties that can decrease over-potential and improve the sensitivity of electrochemical immunosensor. This paper reviews recent advances in the different modified strategies of constructing electrochemical immunosensor based on CNTs for detecting protein cancer biomarkers. CNTs or CNTs hybrid nanomaterials modified electrodes have been firstly introduced as the sensing platforms for the detection of protein cancer biomarkers. On the other hand, CNTs or functional CNTs used as labels in sandwich-type electrochemical immunosensors have been systematically summarized. These novel strategies and the general principles could increase the sensitivity of the immunosensor, thereby overcoming the limitations of its application in the biosensing field. [ABSTRACT FROM AUTHOR]

A sandwich-type electrochemical immunosensor was developed for sensitive detection of carcinoembryonic antigen (CEA) by using ferroferric oxide@silica–amino groups (Fe 3 O 4 @SiO 2 –NH 2 ) as carriers and gold nanoparticles–graphene oxide (GO–AuNPs) as platform. The Fe 3 O 4 @SiO 2 –NH 2 surface was used as linked reagents for co-immobilization of ferrocenecarboxylic acid (Fc-COOH) and secondary anti-CEA (Ab 2 ) to prepare the signal probe, and it also could hasten the decomposition of hydrogen peroxide (H 2 O 2 ) to amplify signals. Differential pulse voltammetry (DPV) was successfully used to quantify CEA. Under the optimized conditions, the designed immunosensor shows an excellent analytical performance wide dynamic response range of CEA concentration from 0.001 ng mL −1 to 80 ng mL −1 with a relatively low detection limit of 0.0002 ng mL −1 ( S / N =3), and high specificity and good reproducibility. The proposed immunosensor was successfully used to determine CEA in spiked human serum samples. [ABSTRACT FROM AUTHOR]

A novel electrochemical immunosensor was developed for the simultaneous detection of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) using Cu2O–graphene oxide–β-cyclodextrin (Cu2O–GO–CD) and β-cyclodextrin–graphene oxide–ferrocenecarboxylic acid (GO–CD–Fc–COOH) as the distinguishable signal probe, and graphene oxide–gold nanoparticles (GO–AuNPs) as the sensor platform. GO–CD displayed excellent solubility in water and rich capture capability to Fc–COOH and the secondary antibody. The proposed immunosensor exhibited an excellent electrochemical performance. The linear ranges were from 0.001 ng mL−1 to 80 ng mL−1 for AFP and CEA with a detection limit of 0.0002 ng mL−1 for AFP and 0.0001 ng mL−1 for CEA. With the merits of acceptable stability, high sensitivity, a wide linear range and a low detection limit, the proposed immunosensor showed great potential for the simultaneous detection of multi-analytes in clinical diagnosis. [ABSTRACT FROM AUTHOR]

In this work, a simple electrochemical immunosensor was developed for the detection of carcinoembryonic antigen (CEA) based on rhombic dodecahedral Cu 2 O nanocrystals–graphene oxide–gold nanoparticles (rCu 2 O–GO–AuNPs). GO as the template and surfactant resulting in rCu 2 O exhibit improved rhombic dodecahedral structure uniformity and excellent electrochemical performance. Moreover, GO was found to be able to effectively improve the long stability of rCu 2 O on the electrode response. Under optimal conditions, the immunosensor showed a low limit of detection (0.004 ng ml −1 ) and a large linear range (0.01–120 ng ml −1 ). This work presents a potential alternative for the diagnostic applications of GO-supported special morphology materials in biomedicine and biosensors. [ABSTRACT FROM AUTHOR]

• A novel method for three-dimensional modeling of end-hook steel fibers in UHPC was proposed. • The dynamic compression behavior of aeolian sand-based UHPC was studied via the split Hopkinson pressure bar technique and 3D mesoscale simulation, and the impact compression finite element model parameters suitable for aeolian sand UHPC were determined. • The effects of strain rate, fiber content and matrix strength on the dynamic mechanical properties of aeolian sand-based UHPC were determined, which have a profound significance for its application in protection engineering. The dynamic mechanical properties of ultra-high performance concrete (UHPC) containing aeolian sand was studied via the split Hopkinson pressure bar technique and three-dimensional mesoscopic numerical simulation. A novel method for three-dimensional modeling of end-hook steel fibers was proposed. Employing the 3D mesoscale model, the dynamic compressive responses of aeolian sand-based UHPC were simulated and analyzed. Simulation results exhibited constitutive relationships and failure patterns that agree well with the impact test results, which verified that the established three-dimensional mesoscopic model enables effective analysis of the dynamic mechanical properties of aeolian sand-based UHPC. Then the effects of strain rate, fiber content and matrix strength on the stress-strain relation and energy evolution process were quantitatively discussed, which provide a basis for the application of aeolian sand-based UHPC. [ABSTRACT FROM AUTHOR]

Rücktitelbild: Zwitterionic Polydopamine Engineered Interface for In Vivo Sensing with High Biocompatibility (Angew. Keywords: acute neuroinflammatory response; antifouling; biointerfacing; in vivo analysis; polydopamine EN acute neuroinflammatory response antifouling biointerfacing in vivo analysis polydopamine 24112 24112 1 12/16/20 20201221 NES 201221 B Eine mit Polydopamin b modifizierte Grenzfläche wurde entwickelt, um die nichtspezifische Proteinbindung in komplexen biologischen Fluiden zu unterdrücken und gleichzeitig den Grenzflächenelektronentransfer, die elektrochemische Stabilität der Elektrode und akute neuroinflammatorische Reaktionen zu verstärken. In ihrer Zuschrift auf S. 23651 zeigen Meining Zhang et al., dass die Grenzfläche mit einer gewebeimplantierbaren Elektrode für die In-vivo-Analyse integriert werden kann. [Extracted from the article]

Ultra-high-performance concrete (UHPC) has been used as an advanced construction material in civil engineering because of its excellent mechanical properties and durability. However, with the depletion of the raw material (river sand) used for preparing UHPC, it is imperative to find a replacement material. Recycled sand is an alternative raw material for preparing UHPC, but it degrades the performance. In this study, we investigated the use of graphene oxide (GO) as an additive for enhancing the properties of UHPC prepared from recycled sand. The primary objective was to investigate the effects of GO on the mechanical properties and durability of the UHPC at different concentrations. Additionally, the impact of the GO additive on the microstructure of the UHPC prepared from recycled sand was analysed at different mixing concentrations. The addition of GO resulted in the following: (1) The porosity of the UHPC prepared from recycled sand was reduced by 4.45–11.35%; (2) the compressive strength, flexural strength, splitting tensile strength, and elastic modulus of the UHPC prepared from recycled sand were enhanced by 8.24–16.83%, 11.26–26.62%, 15.63–29.54%, and 5.84–12.25%, respectively; (3) the resistance of the UHPC to penetration of chloride ions increased, and the freeze–thaw resistance improved; (4) the optimum mixing concentration of GO in the UHPC was determined to be 0.05 wt.%, according to a comprehensive analysis of its effects on the microstructure, mechanical properties, and durability of the UHPC. The findings of this study provide important guidance for the utilisation of recycled sand resources. [ABSTRACT FROM AUTHOR]

Ultra-high-performance concrete (UHPC) has received increasing attention in recent years due to its remarkable ductility, durability, and mechanical properties. However, the manufacture of UHPC can cause serious environmental issues. This work addresses the feasibility of using aeolian sand to produce UHPC, and the mix design, environmental impact, and mechanical characterization of UHPC are investigated. We designed the mix proportions of the UHPC according to the modified Andreasen and Andersen particle packing model. We studied the workability, microstructure, porosity, mechanical performance, and environmental impact of UHPC with three different water/binder ratios. The following findings were noted: (1) the compressive strength, flexural strength, and Young's modulus of the designed UHPC samples were in the ranges of 163.9–207.0 MPa, 18.0–32.2 MPa, and 49.3–58.9 GPa, respectively; (2) the compressive strength, flexural strength, and Young's modulus of the UHPC increased with a decrease in water/binder ratio and an increase in the steel fibre content; (3) the compressive strength–Young's modulus correlation of the UHPC could be described by an exponential formula; (4) the environmental impact of UHPC can be improved by decreasing its water/binder ratio. These findings suggest that it is possible to use aeolian sand to manufacture UHPC, and this study promotes the application of aeolian sand for this purpose. [ABSTRACT FROM AUTHOR]

• Nano-silica enhances the interface properties of UHPC. • Molecular dynamics unravel the interaction mechanisms on the UHPC. • Sol-gel method has a relatively high coating efficiency. The interface properties largely determine the improvement effect of fibers on the cement-based matrix. In this work, nano-silica particles are employed to treat PVA fibers using a sol–gel method, aiming at enhancing interface properties in ultra-high-performance-concrete (UHPC). Based on a comprehensive analysis of SEM-EDS, TG, and Raman spectra, this modification measure has a relatively high coating efficiency and the nano-silica can be evenly distributed and stably adsorb on the surface of PVA fibers. Furthermore, by molecular dynamics simulations, the interaction mechanisms on the fiber-cementitious matrix interface are unraveled. The Ca (from matrix surface) -O (from silica) coordinations lead to chemical bondings, substantially stronger than H bonds formed on PVA/C-S-H interface. As a consequence, the pull-out of SiO 2 modified fibers consumes significantly higher energy than pristine PVA. In conclusion, the coated nano-silica particles not only increase the surface roughness of PVA fibers, which correspondingly improves the physical friction and interlocking effect, but also react with Ca-containing phases in the cementitious matrix, forming new calcium silicate hydrate gels and filling in the cracks. These two mechanisms help increase the UHPC compressive strength by around 10% and the flexural strength by over 26%. [ABSTRACT FROM AUTHOR]

In the past decade, virus-like particles (VLPs) that can encapsulate single or multiple enzymes have been studied extensively as typical nanoreactors for biocatalysis in vitro , yet their catalytic efficiencies are usually inadequate for real applications. These biocatalytic nanoreactors should be engineered like their free-enzyme counterparts to improve their catalytic performance for potential applications. Herein we engineer biocatalytic VLPs for the enhanced synthesis of chiral alcohols. Different methods including directed evolution were applied to the entire bacteriophage P22 VLPs (except the coat protein), which encapsulated a carbonyl reductase from Scheffersomyces stipitis ( Ss CR) and a glucose dehydrogenase from Bacillus megaterium ( Bm GDH) in their capsids. The best variant, namely M5, showed an enhanced turnover frequency (TOF, min -1 ) up to 15-fold toward the majority of tested aromatic prochiral ketones, and gave up to 99% enantiomeric excess in the synthesis of chiral alcohol pharmaceutical intermediates. A comparison with the mutations of the free-enzyme counterparts showed that the same amino acid mutations led to different changes in the catalytic efficiencies of free and confined enzymes. Finally, the engineered M5 nanoreactor showed improved efficiency in the scale-up synthesis of chiral alcohols. The conversions of three substrates catalyzed by M5 were all higher than those catalyzed by the wild-type nanoreactor, demonstrating that enzyme-encapsulating VLPs can evolve to enhance their catalytic performance for potential applications., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Electrochemical tracking of redox-inactive neurochemicals remain a challenge due to chemical inertness, almost no Faraday electron transfer for these species, and the complex brain atmosphere. In this work, we demonstrate a low-cost, simple-making liquid/liquid interface microsensor (LLIM) to monitor redox-inactive neurochemicals in the rat brain. Taking choline (Ch) as an example, based on the difference in solvation energies of Ch in cerebrospinal fluid (aqueous phase) and 1,2-dichloroethane (1,2-DCE; organic phase), Ch is recognized in the specific ion-transfer potential and distinctive ion-transfer current signals. The LLIM has an excellent response to Ch with good linearity and selectivity, and the detection limit is 0.37 μM. The LLIM can monitor the dynamics of Ch in the cortex of the rat brain by both local microinfusion and intraperitoneal injection of Ch. This work first demonstrates that the LLIM can be successfully applied in the brain and obtain electrochemical signals in such a sophisticated system, allowing one new perspective of sensing at the liquid/liquid interface for nonelectrically active substances in vivo to understand the physiological function of the brain.

It is of interest to in vivo monitor the co-dynamics of different substances. However, the tracking of multiple species is still challenging. In this work, we demonstrate an in vivo electrochemical method by using multi-potential step amperometry to in vivo detect ascorbic acid (AA) and oxygen (O2) simultaneously. In order to achieve good selectivity and high sensitivity for both AA and O2, we design a cobalt corrole [Co(tpfc)(py)2] (tpfc = 5,10,15-tris(penta-fluorophenyl) corrole, py = pyridine, denoted as Co-TPFC) and carbon nanotube nanocomposite to modify a carbon fiber microelectrode (Co-TPFC/MWNT/CFE). This Co-TPFC/MWNT/CFE exhibits excellent electrocatalytic properties towards the reduction of O2 preceding a 4e process and facilitates the oxidation of AA at low potential in the physiological environment. Based on this, we realize simultaneous detection of AA and O2 using two-potential steps (one cathodic (-0.2 V) and the other anodic (+0.05 V)) with 1 second step time. Both in vitro and in vivo experiments proved the feasibility of this method. This demonstrated strategy is useful for us to understand various physiological and pathological processes associated with O2 and AA co-dynamics, and also provides an idea for detecting multiple substances simultaneously.

Protein lysine methyltransferase G9a, which catalyzes methylation of lysine 9 of histone H3 (H3K9) and lysine 373 (K373) of p53, is overexpressed in human cancers. This suggests that small molecular inhibitors of G9a might be attractive antitumor agents. Herein we report our efforts on the design of novel G9a inhibitor based on the 3D quantitative structure-activity relationship (3D-QSAR) analysis of a series of 2,4-diamino-7-aminoalkoxyquinazolineas G9a inhibitors. The 3D-QSAR model was generated from 47 compounds using docking based molecular alignment. The best predictions were obtained with CoMFA standard model (q2 =0.700, r2 = 0.952) and CoMSIA model combined with steric, electrostatic, hydrophobic, hydrogen bond donor and acceptor fields (q2 = 0.724, r2 =0.960). The structural requirements for substituted 2,4-diamino-7-aminoalkoxyquinazoline for G9a inhibitory activity can be obtained by analysing the COMSIA plots. Based on the information, six novel follow-up analogs were designed.

Protein kinase CK2 (CK2), a ubiquitous serine/threonine protein kinase for hundreds of endogenous substrates, serves as an attractive anticancer target. One of its most potent inhibitors, CX-4945, has entered a phase I clinical trial. Herein we present an integrated workflow combining shape-based virtual screening for the identification of novel CK2 inhibitors. A shape-based model derived from CX-4945 was built, and the subsequent virtual screening led to the identification of several novel scaffolds with high shape similarity to that of CX-4945. Among them two tricyclic scaffolds named [1,2,4]triazolo[4,3-c]quinazolin and [1,2,4]triazolo[4,3-a]quinoxalin attracted us the most. Combining strictly chemical similarity analysis, a second-round shape-based screening was performed based on the two tricyclic scaffolds, leading to 28 derivatives. These compounds not only targeted CK2 with potent and dose-dependent activities but also showed acceptable antiproliferative effects against a series of cancer cell lines. Our workflow supplies a high efficient strategy in the identification of novel CK2 inhibitors. Compounds reported here can serve as ideal leads for further modifications.