Herein, a facile approach for shape-controlled gold nanoparticle (AuNP) decorated thionine-MoS2 nanocomposites (AuNP-Thi-MoS2) had been reported by using the synergistic effect of MoS2 and Thi. Thi was not only used as an electrochemical indicator, but also as a reducing agent to tune the resulting morphologies of AuNPs. With the ratio of MoS2/Thi decreasing, the shapes of AuNPs changed from spherical, triangle, clover-like to flower-like nanostructures. TEM, XRD and XPS were employed to characterize the formation and chemical composition of AuNP-Thi-MoS2 nanocomposites. On the basis of synthesis, a MoS2-based label-free electrochemical immunosensor had been designed to detect carcino-embryonic antigen (CEA). The proposed immunosensor could detect as low as 0.52 pg mL(-1) CEA with excellent selectivity. Moreover, the expected immunosensor showed high stability and excellent reproducibility, which could detect CEA in human serum with satisfactory results. Therefore, the AuNP-Thi-MoS2 nanocomposites may be considered as a candidate sensing platform for fabrication of simple, label-free and ultrasensitive electrochemical sensors.

Although face-centered cubic (fcc), body-centered cubic (bcc), hexagonal close-packed (hcp), and other structured gold nanoclusters have been reported, it was unclear whether gold nanoclusters with mix-packed (fcc and non-fcc) kernels exist, and the correlation between kernel packing and the properties of gold nanoclusters is unknown. A Au (2,4-DMBT) nanocluster with a shell electron count of 22 has now been been synthesized and structurally resolved by single-crystal X-ray crystallography, which revealed that Au (2,4-DMBT) contains a unique Au kernel consisting of one quasi-fcc-structured Au and one non-fcc-structured Au unit (where 2,4-DMBTH=2,4-dimethylbenzenethiol). Further experiments revealed that the kernel packing greatly influences the electrochemical gap (EG) and the fcc structure has a larger EG than the investigated non-fcc structure.

With the great success of organic light-emitting diodes (OLEDs) based on thermal evaporation techniques, the development of printable materials for inkjet-printing high-performance OLEDs is particularly attractive yet challenging. In this paper, a set of printable Ir­(III)-complexed polydendrimers, poly­[bis­[2-(2,4-difluorophenyl)-4-(4-((2-ethylhexyl)­oxy)­phenyl)­pyridine]­[1-ethyl-5-phenyl-3-propyl-1H-1,2,4-triazole] iridium­(III)] (PIr-D1) and poly­[bis­[2-(2,4-difluorophenyl)-4-(4-((2-ethylhexyl)­oxy)-2,6-dimethylphenyl)­pyridine]­[1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole] iridium­(III)] (PIr-D2), were designed and synthesized via ring-opening metathesis polymerization (ROMP). As a comparison, the iridium precursor complexes bis­[2-(2,4-difluorophenyl)-4-(4-((2-ethylhexyl)­oxy)­phenyl)­pyridine]­[1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole]­iridium­(III) (Ir-D1) and bis­[2-(2,4-difluorophenyl)-4-(4-((2-ethylhexyl)­oxy)-2,6-dimethylphenyl)­pyridine]­[1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole] iridium­(III) (Ir-D2) and the core structure bis­[2-(2,4-difluorophenyl)­pyridine] [1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole] iridium­(III) (Ir-D0) were also synthesized and the corresponding OLEDs were fabricated. Compared with the dendritic iridium complexes Ir-D1 and Ir-D2, the resulting polydendrimers PIr-D2 and PIr-D2 showed enhanced film-forming properties, good thermal stability, and attractive ink rheological characteristics with a suitable viscosity for inkjet-printing. Promising device performance has been achieved for the resulting polydendrimers by both spin-coating and inkjet-printing, showing low driving voltages and relatively high current efficiencies and brightnesses. The results suggest that the construction of polydendritic Ir­(III) complexes is an attractive design strategy for exploring efficient printable light-emitting materials for inkjet-printing high-performance OLEDs.

Industrial development has led to generation of large volumes of wastewater containing heavy metals, which need to be removed before the wastewater is released into the environment. Chemical and electrochemical methods are traditionally applied to treat this type of wastewater. These conventional methods have several shortcomings, such as secondary pollution and cost. Bioprocesses are gradually gaining popularity because of their high selectivities, low costs, and reduced environmental pollution. Removal of heavy metals by sulfate-reducing bacteria (SRB) is an economical and effective alternative to conventional methods. The limitations of and advances in SRB activity have not been comprehensively reviewed. In this paper, recent advances from laboratory studies in heavy metal removal by SRB were reported. Firstly, the mechanism of heavy metal removal by SRB is introduced. Then, the factors affecting microbial activity and metal removal efficiency are elucidated and discussed in detail. In addition, recent advances in selection of an electron donor, enhancement of SRB activity, and improvement of SRB tolerance to heavy metals are reviewed. Furthermore, key points for future studies of the SRB process are proposed.

A bis-branched [3]rotaxane, with two [2]rotaxane arms separated by an oligo(para-phenylenevinylene) (OPV) fluorophore, was designed and investigated. Each [2]rotaxane arm employed a difluoroboradiaza-s-indacene (BODIPY) dye-functionalized dibenzo[24]crown-8 macrocycle interlocked onto a dibenzylammonium in the rod part. The chemical structure of the [3]rotaxane was confirmed and characterized by (1)H and (13)C NMR spectroscopy and high-resolution ESI mass spectrometry. The photophysical properties of [3]rotaxane and its reference systems were investigated through UV/Vis absorption, fluorescence, and time-resolved fluorescence spectroscopy. An efficient energy-transfer process in [3]rotaxane occurred from the OPV donor to the BODIPY acceptor because of the large overlap between the absorption spectrum of the BODIPY moiety and the emission spectrum of the OPV fluorophore; this shows the important potential of this system for designing functional molecular systems.

A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl-hydrazide-catalyzed asymmetric OH-substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2 , 4 mol % (S)-SegPhos, and 10 mol % 2,5-dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.

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A new protocol has been developed for the use of allylic amines as allylating agents in the chiral α-amino acid/palladium-catalyzed asymmetric allylation of α-branched β-ketoesters, providing highly enantioselective access to all-carbon quaternary stereocenters. Notably, the formation of a primary amine, a secondary amine, or ammonia as a byproduct has little influence on the enantioselectivity for the catalytic asymmetric synthesis of structurally diverse α,α-disubstituted β-ketoesters.