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A novel strategy is first presented here to design and construct a good selective and highly sensitive dopamine (DA) biosensor based on single-crystalline CuPc nanowires with a reduced graphene oxide–Nafion film (rGON/CuPcNWs). Metal–organic semiconductor single-crystalline CuPc nanowires with excellent electronic properties and large surface-to-volume ratios were prepared using a physical vapor transport technique and modified onto a glassy carbon electrode (GCE), and exhibited high electrocatalytic activity for DA detection by immobilizing it onto a GCE with a film of the rGON composite. The introduction of a rGO–Nafion film can significantly improve the electrochemical signal of the CuPcNWs. The relevant detection limit toward dopamine is 0.3 nM with a wide linear range from 0.001 μM to 200 μM. The results of the demonstrated biosensor could provide important enlightenment for the design of more sensitive electrochemical biosensors. [ABSTRACT FROM AUTHOR]

A novel and general strategy for the synthesis of a monodispersed Au@CdS core-shell structure with uniform morphology and size through a self-assembly process is proposed here. The obtained negatively charged Au@CdS hybrid core-shell nanoparticles (NPs) are highly selective to dopamine (DA), in the presence of oxidation of ascorbic acid (AA) and uric acid (UA), based on electrostatic interaction. The fabricated biosensor shows a wide linear range from 0.002 to 800 μmol L-1, with a lower detection limit of 0.55 nmol (n = 5, S/N = 3), revealing the high-sensitivity properties. Electrostatic charge plays an important role in the selective electrocatalytic activity of Au@CdS hybrid core-shell nanoparticles, that is the formation of an electrostatic system between the negatively charged Au@CdS hybrid core- shell NPs and the DA cation. The modified electrode is used to achieve the real-time quantitative detection of DA for biological applications, and satisfactory results are obtained. Due to the advantages of the biosensor, its selectivity, sensitivity and stability, it will have a bright future in the field of medical diagnosis. [ABSTRACT FROM AUTHOR]

The coupling of the hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR) to produce clean hydrogen energy with value-added chemicals has attracted substantial attention. However, achieving high selectivity for formate production in the MOR and high faradaic efficiency for H 2 evolution remain significant challenges. In light of this, this study constructs an Ru/Ni(OH) 2 /NF catalyst on nickel foam (NF) and evaluates its electrochemical performance in the MOR and HER under alkaline conditions. The results indicate that the synergistic effect of Ni(OH) 2 and Ru can promote the catalytic activity. At an overpotential of only 42 mV, the current density for the HER reaches 10 mA cm -2 . Moreover, in a KOH solution containing 1 M methanol, a potential of only 1.36 V vs. RHE is required to achieve an MOR current density of 10 mA cm -2 . Using Ru/Ni(OH) 2 /NF as a bifunctional catalyst, employed as both the anode and cathode, an MOR-coupled HER electrolysis cell can achieve a current density of 10 mA cm -2 with a voltage of only 1.45 V. Importantly, the faradaic efficiency (FE) for the hydrogen production at the cathode and formate (HCOO - ) production at the anode approaches 100%. Therefore, this study holds significant practical implications for the development of methanol electro-oxidation for formate-coupled water electrolysis hydrogen production technology., Competing Interests: The authors state that none of the work presented in this study may have been influenced by any known conflicting financial interests or personal ties., (This journal is © The Royal Society of Chemistry.)

We report the synthesis and self-assembly of a new pi-conjugated dichalcone substituted carbazole-based low molecular mass organogelator. It could form stable gels in most halogen-aromatic solvents. The transmission electron microscopy (TEM) images revealed that the gel formed fibrous structures with diameter of 50-100 nm, which consisted of several thinner fibers. The FT-IR, UV-vis and XRD results suggested that the H-bonds and pi-pi interactions were the main driving forces for the formation of the self-assembled gel, in which the U-shaped molecules were stacked into lamellar structures. The fluorescent spectra showed that the emission of the xerogel red-shifted markedly compared with the sol state, which resulted from the aggregation of the molecules.

A new series of binary organogels, which showed good gelated capability and strongly enhanced fluorescence emission, were designed and prepared by simply mixing two components of L-tartaric acid and alkoxyl substituted stilbazoles. It was found that L-tartaric acid could not only introduce stilbazole with fluorescent property into the gel system, but also provided a main motif for the formation of the gel-phase via multiple hydrogen bonds. Meanwhile, pi-pi interactions between the complexes also played a key role in the gel formation. The decreased nonradiative process, suggested by the longer fluorescent lifetime of aggregates than that of monomers and the presence of the J-aggregation for the aggregated state, favored the enhanced fluorescence emission.