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Implanted medical devices are widely used in clinic for disease treatment, but they generally suffer from the bio‐fouling problem which leads to the reduction of service life and loss of therapeutic effects. Herein, an eco‐friendly method based on polydopamine (PDA) fast deposition is developed to construct anti‐fouling and antibacterial surface on polyurethane (PU). The self‐adhesive layer of PDA contributes to the formation of a platform with active sites for further antibacterial and hydrophilic modification. Polyhexamethylguanidine (PHMG) as antibacterial ingredient and chondroitin sulfate (CS) as hydrophilic component covalently bind on PDA platform, which successively helps to form PU‐PDA/PHMG/CS. The resultant surface demonstrates the excellent property of anti‐protein adsorption (96.8%), anti‐bacterial ability (99.9%), and cell compatibility (95.0%), which would have great potential for medical application. [ABSTRACT FROM AUTHOR]

Here we established a palm‐sized electrochemical sensor for the determination of cell‐released superoxide anions (O2.−) based on a self‐developed portable potentiostat (xenSTAT) which can perform fast analysis with visual real‐time data and customizable parameters. The xenSTAT was equipped with Bluetooth and USB interfaces, thus being able to be connected with both smartphones and computers for electrochemical analysis. A novel Nanozyme based on Mnx(PO4)y monolayer modified porous carbon cubic was synthesized and used as functional material on the surface of working electrode. By using cyclic voltammetry (CV) and chronoamperometry, xenSTAT was demonstrated to exhibit satisfying sensitivity and excellent stability for real‐time monitoring of O2.− released from cancer cells. With decreased cost, customizable development, small size and convenient usage, the xenSTAT described in this work could promote the commercialization and widespread of in‐house built electrochemical sensors for the monitoring of O2.− in the future. [ABSTRACT FROM AUTHOR]

Nanocarriers are employed to deliver photosensitizers for photodynamic therapy (PDT) through the enhanced penetration and retention effect, but disadvantages including the premature leakage and non‐selective release of photosensitizers still exist. Herein, we report a 1O2‐responsive block copolymer (POEGMA‐b‐P(MAA‐co‐VSPpaMA) to enhance PDT via the controllable release of photosensitizers. Once nanoparticles formed by the block copolymer have accumulated in a tumor and have been taken up by cancer cells, pyropheophorbide a (Ppa) could be controllably released by singlet oxygen (1O2) generated by light irradiation, enhancing the photosensitization. This was demonstrated by confocal laser scanning microscopy and in vivo fluorescence imaging. The 1O2‐responsiveness of POEGMA‐b‐P(MAA‐co‐VSPpaMA) block copolymer enabled the realization of self‐amplified photodynamic therapy by the regulation of Ppa release using NIR illumination. This may provide a new insight into the design of precise PDT. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a metal‐organic frameworks‐based porous carbon was explored for glucose oxidase immobilization and glucose sensing. ZIF‐67 was chosen as the precursors for the calcination treatment. The formed Co nanoparticles induced the graphitization of the carbon during the carbonization, resulting in a good conductivity. The followed HCl treatment partly removed the formed Co nanoparticles to give a larger specific surface area of the porous carbon due to the generated space voids from the dissolved Co nanoparticles. The resulting MOFs‐derived porous carbon show an improved loading performance toward glucose oxidase, and fast electron transfer was also demonstrated. This work proves the MOFs‐derived porous carbon as a novel and outstanding platform for the enzymatic electrocatalysis for the sensors and energy conversion devices. [ABSTRACT FROM AUTHOR]

Abstract: The performance of electrochemical sensors is mainly limited by the intrinsic properties of electrocatalysts fabricated on the electrode. Introducing a p‐n heterojunction into semiconducing electrocatalysts is an effective strategy to enhance the sensing performance. In this paper, p‐n‐heterojunction‐based CuO/CeO2 nanocomposites were synthesized by a simple hydrothermal process, and the effect of different Cu/Ce molar ratios was explored. p‐CuO/n‐CeO2 was found to exhibit higher conductivity and electrocatalytic activity toward the target superoxide anion (O2.−) when compared to both bare CuO and CeO2. Characterization shows that different Cu/Ce ratios in p‐CuO/n‐CeO2 materials result in a considerable variation in the Ce3+/Ce4+ level, and energy band gap of CeO2, greatly affecting the electrochemical performance of p‐CuO/n‐CeO2. Under optimized conditions, these sensors exhibit high sensitivity and low detection limit toward O2.−. These results demonstrate that the performance of semiconductor‐based electrochemical sensors may be enhanced by the electron‐transfer process of p‐n junction interfaces. [ABSTRACT FROM AUTHOR]

A sensitive and selective amperometric H2O2 biosensor was obtained by utilizing the electrodeposition of Pt flowers on iron oxide-reduced graphene oxide (Fe3O4/rGO) nanocomposite modified glassy carbon electrode (GCE). The morphology of Fe3O4/rGO and Pt/Fe3O4/rGO was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The step-wise modification and the electrochemical characteristics of the resulting biosensor were characterized by cyclic voltammetry (CV) and chronoamperometry methods. Thanks to the fast electron transfer at the Pt/Fe3O4/rGO electrode interface, the developed biosensor exhibits a fast and linear amperometric response upon H2O2. The linear range of Pt/Fe3O4/rGO is 0.1∼2.4 mM (R2=0.998), with a sensitivity of 6.875 μA/mM and a detection limit of 1.58 μM (S/N=3). In addition, the prepared biosensor also provides good anti-interferent ability and long-term stability due to the favorable biocompatibility of the electrode interface. The proposed sensor will become a reliable and effective tool for monitoring and sensing the H2O2 in complicate environment. [ABSTRACT FROM AUTHOR]

Whereas metal-organic frameworks (MOFs) are being widely explored in the application of electrocatalysis, the electro-inert organic ligands in MOFs have negative effects on electron transfer. Here, we suggest a facile electrochemical cathodization treatment for the controllable evolution of a Cu-MOF to improve its electrocatalytic performance. When a cathodic potential was applied, Cu-based structures evolving from Cu-MOF with different crystal phases, surface compositions, and morphologies were harvested by controlling the cathodization time. The obtained copper-based structures were found to have much higher activities than the as-synthesized Cu-MOF for glucose electrocatalysis in alkaline media. A 60 second cathodization treatment resulted in the largest sensitivity for glucose electrocatalytic sensing. [ABSTRACT FROM AUTHOR]

Maltose covalently bonded to silica was prepared by using carbonyl diimidazole as a cross-linker and employed as a stationary phase for hydrophilic interaction liquid chromatography. The column efficiency and the effect of water content, buffer concentration, and pH value influenced on retention were investigated. The separation or enrichment selectivity was also studied with nucleosides, saccharides, amino acids, peptides, and glycopeptides. The results indicated that the stationary phase processed good separation efficiency and separation selectivity in hydrophilic interaction liquid chromatography mode. Moreover, a two-dimensional hydrophilic interaction liquid chromatography× reversed-phase liquid chromatography method with high orthogonality was developed to analyze the Ginkgo Biloba extract fractions. The development of this two-dimensional chromatographic system would be an effective tool for the separation of complex samples of different polarities and contents. [ABSTRACT FROM AUTHOR]

The investigation of highly efficient catalysts for the electrochemical oxidation of glucose is the most critical challenge to commercialize nonenzymatic glucose sensors, which display a few attractive superiorities including the sufficient stability of their properties and the desired reproducibility of results over enzyme electrodes. Herein we propose a new and very promising catalyst: Pt cubes well-dispersed on the porous Cu foam, for the the electrochemical oxidation reaction of glucose in neutral media. The catalyst is fabricated in situ on a homemade screen-printed carbon electrode (SPCE) substrate through initially synthesizing the three-dimensional (3D) porous Cu foam using a hydrogen evolution assisted electrodeposition strategy, followed by electrochemically reducing the platinic precursor simply and conveniently. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) proofs demonstrate that Pt cubes, with an average size (the distance of opposite faces) of 185.1 nm, highly dispersed on the macro/nanopore integrated Cu foam support can be reproducibly obtained. The results of electrochemical tests indicate that the cubic Pt-based catalyst exhibits significant enhancement on the catalytic activity towards the electrooxidation of glucose in the presence of chloride ions, providing a specific activity 6.7 times and a mass activity 5.3 times those of commercial Pt/C catalysts at −0.4 V (vs. Ag/AgCl). In addition, the proposed catalyst shows excellent stability of performance, with only a 2.8 % loss of electrocatalytic activity after 100 repetitive measurements. [ABSTRACT FROM AUTHOR]

Improving the electrocatalytic activity of Pt-based catalysts is of great importance for the development of heterogeneous catalysis, fuel cells, and analytical sensors. Herein, we achieve significant enhancement of the catalytic activity of Pt-Pd bimetallic materials towards glucose electrooxidation by introducing porous architectures with three-dimensional dendritic microstructures, which were fabricated in situ on desired substrates through electrochemically reducing precursors along with periodic bubbling caused by the intermittent liberation of hydrogen. The synthesized Pt-Pd materials were characterized by SEM, nitrogen adsorption/desorption, energy dispersive spectroscopy, XRD, inductively coupled plasma optical emission spectrometry, and electrochemical techniques. Encouragingly, an extra-large active surface area of up to 80.8 m2 g−1 was obtained for the porous Pt-Pd nanostructures, almost 3.8 times that of the Pt-Pd alloys prepared by standard electrodeposition techniques. As a result, the synthesized Pt-Pd with porous frameworks exhibited remarkably improved electrocatalytic properties for glucose oxidation in neutral media, with 1.5 times the mass activity compared to the conventional Pt-Pd structure. In addition, the porous Pt-Pd catalysts could be reused at least 100 times in the presence of chloride ions, with negligible loss of activity. [ABSTRACT FROM AUTHOR]

This work presents a disposable bismuth-antimony film electrode fabricated on screen-printed electrode (SPE) substrates for lead(II) determination. This bismuth-antimony film screen-printed electrode (Bi-SbSPE) is simply prepared by simultaneously in situ depositing bismuth(III) and antimony(III) with analytes on the homemade SPE. The Bi-SbSPE can provide an enhanced electrochemical stripping signal for lead(II) compared to bismuth film screen-printed electrodes (BiSPE), antimony film screen-printed electrodes (SbSPE) and bismuth-antimony film glassy carbon electrodes (Bi-SbGC). Under optimized conditions, the Bi-SbSPE exhibits attractive linear responses towards lead(II) with a detection limit of 0.07 µg/L. The Bi-SbSPE has been demonstrated successfully to detect lead in river water sample. [ABSTRACT FROM AUTHOR]

New electron paramagnetic resonance (EPR) oximetry probes were identified in the class of carbon black materials. These compounds exhibit very high oxygen sensitivity and favorable EPR characteristics for biological applications. At low pO2, the linewidth is particularly sensitive to changes in oxygen tension (sensitivity of 750 mG/mmHg). The application of the probes for oximetry was demonstrated in vivo: the pO2 was measured in muscle in which the blood flow was temporarily restricted as well as in tumor-bearing mice during a carbogen breathing challenge. The responsiveness to pO2 was stable in muscle for at least 3 months. No toxicity was observed using these materials in cellular experiments and in histological studies performed 2, 7, and 28 days after implantation. In view of their EPR characteristics (high sensitivity) as well as the well-characterized production procedure that make them available on a large scale, these probes can be considered as very promising tools for future developments in EPR oximetry. Magn Reson Med 51:1272-1278, 2004. © 2004 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The cover picture shows a sensitive and selective amperometric H2O2 biosensor which was obtained by utilizing the electrodeposition of Pt flowers on iron oxide‐reduced graphene oxide (Fe3O4/rGO) nanocomposite modified glassy carbon electrode (GCE). Details are discussed in the article by Xueling Zhao et al. on page 1518. [ABSTRACT FROM AUTHOR]

The Inside Back Cover picture shows that the cathodization treatment on Cu–MOF results in the evolution of a structure with improved electrocatalytic activity for glucose oxidation. More information can be found in the Communication by H. Zhao, M. Lan and co‐workers on page 246 in Issue 2, 2017 (DOI: 10.1002/celc.201600625). [ABSTRACT FROM AUTHOR]