Highly Stretchable and Conductive Core–Sheath Chemical Vapor Deposition Graphene Fibers and Their Applications in Safe Strain Sensors

Highly stretchable and conductive core–sheath nanofibers are significant for flexible and wearable microelectronics. Core–sheath fibers were massively fabricated from ultralong chemical vapor deposition (CVD)-grown graphene bundles. They exhibited superior conductivity and excellent mechanical properties that exceeded those of the reduced graphene oxide fibers. The intrinsic dynamic fracture procedure and mechanism of the core–sheath nanofibers were investigated. Furthermore, safe strain sensors based on as-prepared core–sheath CVD graphene fibers have been demonstrated as a proof-of-concept application. The performance of strain sensors has been greatly improved by using CVD graphene fibers

MMP-2 (a) and MMP-9 (b) expression of C, Us, S, and Us+S groups.

<p>Arrow: small cells. Data are presented as mean ± SD values. Statistical significance was determined by one-way ANOVA Dunnett’s t-test. *p<0.05 and **p<0.01 <i>vs.</i> control group. Scale bar = 50 µm.</p

PCNA (a) expression and TUNEL staining (b) in tumors of C, Us, S, and Us+S groups.

<p>Numbers are mean ± SD values. Statistical significance was determined by one-way ANOVA Dunnett’s t-test. *p<0.05 and **p<0.01 <i>vs.</i> control group. Scale bar = 50 µm.</p

Inhibitory effect of <i>scutellarin</i> and ultrasound on tumor growth.

<p>(a) Gross view of a representative globular SAS xenograft tumor on the rear area of a nude mouse. The tumor mass in the C, S, and Us groups was more evident than that in the Us+S group. (b) Growth curve of SAS tumors. Relative volume (V_R) of tumor growth was calculated as a measure of tumor growth for the C, Us, S, and Us+S groups. Data are mean ± SD values; n = 10 to 12 mice per group. **p<0.01 <i>vs.</i> control. Scale bar = 10 mm.</p

Induction of reactive oxygen species (ROS) generation in SAS cells by <i>scutellarin</i> and ultrasound.

<p>(a) Intracellular ROS production was observed under fluorescence microscopy by 2′,7′-dichlorofluorescin diacetate (DCFH-DA) staining for the C, Us, S, and Us+S groups. Light green fluorescence shows ROS levels in the cytoplasm. Scale bar = 100 µm. (b) Cells were stained with DCFH-DA and analyzed by flow cytometry. (c) Relative ROS levels in terms of mean fluorescence are shown as ratios compared to the C group. Data shown are the mean ± SD values calculated from representative measurements obtained from at least 3 independent experiments. Statistical significance was determined by one-way ANOVA S-N-K test. *p<0.01 vs. control; *# p<0.05 vs. Us+S groups. The increase in ROS generation for Us+S is much less than sonodynamic effect.</p

CD105 (*) expression (a) and D2–40 (*) expression (b) and microvessel density (MVD-CD105) and lymphatic vessel density (LVD-D2–40) for C, Us, S, and Us+S groups.

<p>Data are mean ± SD values. Statistical significance was determined by one-way ANOVA Dunnett’s t-test. *p<0.05 and **p<0.01 <i>vs.</i> control group.</p

Scanning electron microscopy of SAS cells.

<p>(a) Control cells. (b) Cells after sonication at 0.05 W/cm² for 1 min. (c) Cells treated with 15 nM of scutellarin. (d) Cells treated with 15 nM of <i>scutellarin</i> followed by sonication at 0.05 W/cm² for 1 min. Scale bar = 20 µm.</p

Schematic diagram of sonication devices for the <i>in vitro</i> and <i>in vivo</i> experiments.

<p>(a) The tone-burst ultrasonic transducer (1.0 MHz center frequency, 10% duty factor) was fixed by aluminum stents facing upward. The culture dish was placed above the center of the transducer for the <i>in vitro</i> experiments. (b) The tone-burst ultrasound signal was applied through a tapered aluminum buffer head with its front surface directly in contact with the skin above the tumor site for the <i>in vivo</i> experiments.</p

Inhibition of SAS cell migration and invasion by <i>scutellarin</i> and ultrasound.

<p>(a) Wound healing assay (scale bar = 100 µm) for C, Us, S, and Us+S groups. (b) and (c): Effect of S and Us treatments on SAS cell migration after 24 h (b) and invasion after 48 h (c), respectively, as assessed by transwell migration and invasion assay. (d) Number of stained cells after treatment. The average of 10 fields was counted in 3 replicate studies for each cell line. Data are mean ± SD values of 3 experiments (n = 3). Statistical significance was determined by one-way ANOVA Dunnett’s t-test. *p<0.05; **p<0.01 <i>vs.</i> control cells.</p

Solid-State Reaction Synthesis of a InSe/CuInSe₂ Lateral p–n Heterojunction and Application in High Performance Optoelectronic Devices

Graphene-like layered semiconductors are a new class of materials for next generation electronic and optoelectronic devices due to their unique electrical and optical properties. A p–n junction is an elementary building block for electronics and optoelectronics devices. Here, we demonstrate the fabrication of a lateral p–n heterojunction diode of a thin-film InSe/CuInSe₂ nanosheet by simple solid-state reaction. We discover that InSe nanosheets can be easily transformed into CuInSe₂ thin film by reacting with elemental copper at a temperature of 300 °C. Photodetectors and photovoltaic devices based on this lateral heterojunction p–n diode show a large photoresponsivity of 4.2 A W^–1 and a relatively high light-power conversion efficiency of 3.5%, respectively. This work is a giant step forward in practical applications of two-dimensional materials for next generation optoelectronic devices