Volume 9 Issue 3, March 2017

This work focuses on the thermoelectric properties inherent to p-type GeTe by tuning the carrier concentration. Compared with PbTe and SnTe, GeTe shows the highest Seebeck coefficient (a) and power factor (b) in the important carrier concentration range of 1–3 × 10²⁰ cm⁻³. Provided all are fully optimized in carrier concentrations, GeTe shows the highest thermoelectric figure of merit, zT at all temperatures (c). This originates from its highest degeneracy of the first valence band (along Σ line) in the low temperature phase, and the smallest effective masses for both L and Σ bands in the high temperature phase (d).

An array-based system for cancer cell sensing has been developed by using a ‘chemical nose/tongue’ approach that exploits subtle changes in the physicochemical nature of different cell surfaces. This electrochemical sensing array has ultrahigh sensitivity, which reaches low detection limit (about 1 cell) for the detection of single-cell type and can discern different cell types at level as low as 100 cells with high accuracy, such as (i) different cell types; (ii) cancerous, multidrug-resistant cancerous and metastatic human breast cells; (iii) artificial circulating tumor cells (CTCs).

Structural color coatings are prepared using the electrophoretic deposition (EPD) of SiO₂ and carbon black particles. The arrangement of the particle array is controlled by varying the deposition condition. The angular dependence of the structural color changes dramatically with the arrangement of the particle array. Variously colored coatings can be produced on materials with complicated shapes.

We developed a self-assembled nanocomposite photoanode composed of epitaxial BiVO₄ (BVO) matrix embedded with WO₃ (WO) mesocrystal for photoelectrochemical (PEC) water splitting in the visible-light regime. The well-defined WO₃-BiVO₄ interface and controllable thickness provide a template for the fundamental understanding of photoactivity in the nanocomposite. The interfacial coupling of the mesocrystal and matrix improves the separation of photoexcited carriers and the properties of charge transfer, resulting in a significantly enhanced PEC performance. The utilization of the interface-to-volume ratio to optimize the charge interaction of the nanocomposite is essential for the advance design of novel mesocrystal-embedded nanocomposite photoelectrodes.

Electrical therapy has been recognized as an alternative medical treatment for tissue repair in recent years. The principle of electrical therapy is the modulation of cell behavior by applying electrical signals. However, to date, the effectiveness of electrical therapy is limited. Herein, we developed electroresponsive and conductive polydopamine-polypyrrole microcapsules on the surfaces of electrical therapy devices, which can locally and precisely release drugs and apply electrical stimulation to modulate cell behaviors.

Crystalline Ga₂O₃ is an ultra-wide bandgap oxide semiconductor, but electron conduction in amorphous Ga₂O_x has never been attained to date. Here we succeeded in converting amorphous Ga₂O_x to a semiconductor with the bandgap of ~4.12 eV and the electron mobility ~8 cm² V⁻¹ s⁻¹. The key is to suppress charge compensation defects by increasing the film density and suppress formation of oxygen-poor and oxygen-excess defects. It produces thin-film transistors and Schottky diodes with high on currents and on/off ratios.

A novel chitosan–fibrin (CF) injectable, self-healing hydrogel (modulus ~1.2 kPa) is developed. The CF hydrogel has excellent self-healing properties and induces vascular endothelial cells to form capillary-like structure. The self-healing and angiogenic capacities are associated with the interpenetrating network structure of the hydrogel. The hydrogel degrades ~70% in 2 weeks. Injection of the CF hydrogel alone can promote angiogenesis in the perivitelline space of zebrafish and rescue the blood circulation in ischemic hindlimbs of mice. This biomimetic hydrogel has potential applications in vascular repair.

Highly transparent and conductive three-dimensional ITO branches were used as a scaffold to improve the optical properties of electrochromic device (ECD). During the operation of ECD, Ag nanoparticles were spatially separated on ITO branches. This unique geometry of ITO branch and Ag nanoparticle showed a strong plasmonic light absorption, resulting in deep black state (average reflectance of 8.78%). Also, the ECD could reversibly switch the three states of transparent, mirror and black states for 10 000 cycles without degradation.

We report a new carbon allotrope belonging to a class of topological nodal line semimetals, based on global optimization and first-principles density functional calculations. The new carbon phase in monoclinic C2/m space group, termed m-C₈, consists of five-membered rings with sp³ hybridized bonds and sp²-bonded carbon networks. The band structure exhibits linear dispersions around the Fermi level where the valence and conduction bands touch each other. Based on the analysis of X-ray diffraction spectra and enthalpy-pressure curves, we propose that m-C₈ can be present in detonation soot and a phase transition from graphite to m-C₈ can occur under pressure.

Magneto-core–shell nanoassemblies by loading μ-oxo-bridged Fe complex (Fe(salen) (core)) inside PCL-b-PPy block copolymers (shell) are fabricated, without the use of common magnetites and toxic solvents. By taking a surface functionalization with natural biomolecules (bovine serum albumin/gum arabic (BSA/GA)), the nanoassemblies endow to hold tunablity of core-size and magnetism, biocompatibility, and colloidal stability. Moreover, distinguishing their multifunctional features of cancer targeting include magneto-guided drug delivery, MRI, and triggered hyperthermia in responsive to multi (magnetic, thermo, and pH) stimuli, which allow them a promising potential for a wide-variety of ‘minimally-invasive’ theranostic clinics, as an alternative candidate to conventional magnetite-based anticancer targeting.

Schematic illustration of nanoformulated curcumin accelerates wound healing. (a) Curcumin nanoformulation through electrospinning greatly enhances its solubility. (b) Topically applied Curcumin/Gelatin nanofibrous mat releases bioactive curcumin to mobilize wound site fibroblasts by enhancing both cell proliferation and migration, a process partially mediated by Dickkopf-related protein-1-regulated Wnt/β-catenin pathway signaling. In the mean time, fibroblasts decreased the expression of monocyte chemoattractant protein-1, leading to lasting inhibition of inflammatory response during the healing process. As a result, wound environment turns out to be more in favor of physiological healing, with faster re-epithelialization, granulation tissue formation, as well as collagen deposition and matuaration from proliferative fibroblasts.

We present a novel biodegradable cancer therapeutic system based on DNAzyme nanoflowers for targeted dual gene silencing. The therapeutic system was constructed by copying rolling circle amplification template to produce long single-stranded DNAs with cell targeting and dual gene silencing capability. The structure of the nanoflowers collapsed at acidic pH due to decomposition of the co-assembled magnesium pyrophosphate, generating Mg²⁺ ions which act as cofactors for the DNAzymes and increase their ability to recognize and cleave target mRNAs. Considering its enhanced therapeutic effect and biocompatibility, this platform is expected to be of great interest for clinical treatment of cancers.

Novel magnetophoretic device resembling a spider web network, being integrated with planar Hall resistance sensor, has been developed for the simultaneous concentric transportation and monitoring of superparamagnetic streptavidin-loaded cargos (particles). The multilayer sensor and permalloy network tracks have been fabricated by successive micropatterning processes of film deposition and photolithography. The transporting particles are precisely manipulated on the magnetic tracks towards the sensor by an external magnetic field, where the sensor signal varies with the accumulated particle number. This effective collection and monitoring platform could open novel bioassays overcoming limitation of Brownian transportation of biomolecules to the sensor surface.

The electrochemical activity of Ni²⁺/³⁺ redox couple in the mixed-polyanionic framework Na₄Ni₃(PO₄)₂(P₂O₇) is reported for the first time. The application of a carbon coating and the use of an ionic liquid-based electrolyte enable the reversible Na⁺ (de-)insertion in the host structure accompanied by the redox activity of Ni²⁺/³⁺ at operating voltages as high as 4.8V vs. Na/Na⁺. These results represent an important step towards the realization of Ni- based mixed polyanionic compounds with improved electrochemical activity and pave ways for the discovery of new Na-based cathode materials and the formulation of Na-ion batteries with very high operating voltages.

A self-protected nanovehicle with peptide-mediated core/satellite/shell structure was constructed for precise imaging of protease cathepsin B (Cat B) in situ and subsequent Cat B-responsive drug release. The self-protected nanovehicles have demonstrated excellent resistant ability to nonspecific enzymolysis, thereby keeping the embedded peptide-based molecular probes with core/satellite structure intact until reaching the target organelle.

The microstructure dynamics of electrode materials during battery cycling is dictated by the coupling between their lattice, charge and orbital characteristics, as shown in the schematic. TEM monitoring enables tracking lattice and chemical bonding at high spatial resolution, and thereby establishes the relationship between structure and performances.

This review summarizes recent results on the syntheses and characterization of the non-native phases of h-CoO, h-MnO and c-ZnO transition metal monoxides compared to their native phases. The investigation of the size- and phase-selective synthetic methods, formation mechanism and unique physicochemical properties of non-native transition metal monoxides would have an enormous impact on materials chemistry and open a promising avenue for magnetic, electronic, and spintronic applications.