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With the ongoing progress in exploring novel fabrication methods, topics towards high-performance, simply fabricated organic light-emitting diodes (OLEDs) have received a great deal of attention. Brush-coating is a superior liquid phase thin film deposition technology with nearly 100% material utilization, which has remarkable potential application in depositing large-area uniform films. Here, a uniform and smooth polymer hole-injection layer and a small molecule light-emitting layer are successfully fabricated through brush-coating by controlling the wetting and dewetting processes. White phosphorescent OLEDs with blue and orange complementary colours are constructed by continuously brush-coating the hole-injection layer and small molecule light-emitting layer. The brush-coated white device possesses a peak luminance of 29 190 cd m−2 and a current efficiency of 29.3 cd A−1, which are comparable to those of the spin-coated device with the same structure. In addition, the brush-coated red, green and blue phosphorescent OLEDs exhibit excellent performance in our research with peak current efficiencies of 16.7, 30.4 and 20.9 cd A−1, respectively. These results demonstrate that the brush-coating technology is a simple and effective strategy for depositing uniform organic films and, consequently, fabricating a high-performance device. What's more, brush-coating is expected to be applied to the best-to-date, large-area, flexible or patterned OLEDs in the future. [ABSTRACT FROM AUTHOR]

Thiophenol (PhSH) is toxic to the environment and biological systems although it is an indispensable material in the synthetic processes of chemical products. In this work, we designed and synthesized a malonitrile-based colorimetric and deep-red emission fluorescent dosimeter specifically for thiophenol detection by switching on the intramolecular charge transfer process. The 2,4-dinitrobenzene moiety in the probe could be cleaved by thiophenol, which led to strong deep-red fluorescence increase at 645 nm (50-fold) with a low detection limit of 9 nM. The maximum plateau of emission intensity was reached in about 30 min after the addition of thiophenol. Simultaneously, the presence of thiophenol could result in a prominent color change from orange to blue. Furthermore, the dosimeter could quantitatively sense thiophenol spiked in water samples and successfully visualize thiophenol in living SH-SY5Y cells. [ABSTRACT FROM AUTHOR]

It is challenging to simultaneously discriminate two or three biothiols from each other due to their structural similarities as well as reactions sites. The development of multiple-signal fluorescent probes would be a promising way to overcome this issue. Herein, a two-separated-emission fluorescent probe for biothiols was developed based on the combination of nitrobenzofurazan (NBD) and phenanthroimidazole fluorophores linked by a facile ether bond. In the presence of Cys and Hcy, the probe in DMF–H2O demonstrates two separate fluorescence emissions at 480 and 550 nm upon excitation of two independent wavelengths. However, addition of GSH to the probe only leads to blue fluorescence at 480 nm. This difference can be reasonably ascribed to the fact that the NBD–GSH intermediate, unlike NBD–Cys/Hcy, cannot undergo an intramolecular cyclization–rearrangement reaction. The probe exhibits a rapid response with low limits of detection (14.7 nM for Cys, 14.4 nM for Hcy, and 13.4 nM for GSH) with large concentration ranges of 0–100 μM for Cys/Hcy and 0–200 μM for GSH. Furthermore, the probe is successfully applied to simultaneously distinguish endogenous Cys, Hcy, and GSH in living HeLa cells and zebrafish models. [ABSTRACT FROM AUTHOR]

Zn2+ plays fundamental roles in cellular metabolism and apoptosis, as well as neurotransmission. However, how to fast detect Zn2+ in biology is still challenging and meaningful. In this study, we rationally synthesized a simple OFF–ON fluorescent probe for fast detection of Zn2+ based on intramolecular charge transfer and chelation-enhanced fluorescence. Addition of Zn2+ into the probe induced a significant fluorescence enhancement with a bathochromic shift of 55 nm. Moreover, the probe demonstrated excellent sensitivity (detection limit = 0.072 μM) and outstanding selectivity toward Zn2+ and an ultra-fast response rate of two seconds. The recognition mechanism of the probe toward Zn2+ was fully confirmed by HRMS and 1H NMR spectra, as well as TDDFT calculations. Furthermore, the probe could rapidly visualize Zn2+ in living cells and zebrafish models in bioimaging experiments with low cytotoxicity and good biocompatibility. [ABSTRACT FROM AUTHOR]

In this paper, we perform a systematic and rigorous study to evaluate the Ohmic nature of the top-contact formed by the monolayer ReS2 (mReS2) and metals (gold, silver, platinum, nickel, titanium, and scandium) by means of first-principles density functional theory calculations. We investigate the potential barrier, charge transfer and atomic orbital overlap at the mReS2–metal interface in consideration of van der Waals forces to understand how efficiently carriers could be injected from the metal contact to the mReS2 channel. ReS2 is physisorbed on Au and Ag, which leads to little perturbation of its electronic structures and forms a larger Schottky contact and a higher tunnel barrier at the interface. ReS2 is chemisorbed on Ti and Sc, where the bonding strongly perturbs the electronic structures and is found to be purely Ohmic. The bonding of ReS2 on Pt and Ni lies between these two extreme cases, demonstrating an intermediate behavior. These findings not only provide an insight into the mReS2–metal interfaces but may also prove to be instrumental in the future design of ReS2-based devices with good performance. [ABSTRACT FROM AUTHOR]

Ultra-thin palladium nanosheets (PdNSs) with a diameter of ∼0.8 nm and characteristic (110)-oriented flat planes were synthesized by confined growth inside lamellar micelles. The rationally designed pyridinium-type surfactant with a long carbon chain (e.g., C22) is a crucial factor for the construction of PdNSs. The other synthesis parameters, including the reduction rate and concentration of reactants, should be carefully controlled. Owing to the ultra-thin feature, PdNSs performed superior electrocatalytic activity towards glycerol oxidation. [ABSTRACT FROM AUTHOR]

In this paper, we perform a systematic and rigorous study to evaluate the Ohmic nature of the top-contact formed by the monolayer ReS 2 (mReS 2 ) and metals (gold, silver, platinum, nickel, titanium, and scandium) by means of first-principles density functional theory calculations. We investigate the potential barrier, charge transfer and atomic orbital overlap at the mReS 2 -metal interface in consideration of van der Waals forces to understand how efficiently carriers could be injected from the metal contact to the mReS 2 channel. ReS 2 is physisorbed on Au and Ag, which leads to little perturbation of its electronic structures and forms a larger Schottky contact and a higher tunnel barrier at the interface. ReS 2 is chemisorbed on Ti and Sc, where the bonding strongly perturbs the electronic structures and is found to be purely Ohmic. The bonding of ReS 2 on Pt and Ni lies between these two extreme cases, demonstrating an intermediate behavior. These findings not only provide an insight into the mReS 2 -metal interfaces but may also prove to be instrumental in the future design of ReS 2 -based devices with good performance.

High nitrogen-doped carbon/Mn3O4 composites were synthesized by annealing nitrogen-rich Mn-based coordination polymer particles, and investigated by electron microscopy, X-ray diffraction, and electrochemical experiments. To assess the performance of high nitrogen-doped hybrids as electrode materials in supercapacitors, cyclic voltammetry and galvanostatic charging-discharging measurements are performed. High nitrogen-doped carbon/Mn3O4 composites are charged and discharged faster and have higher capacitance than carbon/Mn3O4 nanostructures with low nitrogen amounts and other reported ones. The capacitance of the high nitrogen-doped carbon/Mn3O4 is 94% retained after 1000 cycles at a constant current. These improvements can be attributed to the nitrogen-doped carbon matrix, which promotes fast Faradaic charging and discharging of the Mn3O4 motifs. The nitrogen-doped carbon/Mn3O4 composites could be a promising candidate material for a high-capacity, low-cost, and environmentally friendly electrode for supercapacitors.