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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]

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]

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 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]

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]