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Single base mismatch can always connect with various gene-related diseases, whose determination has aroused widespread interest. So far, various methods have been developed to determine the common base mismatch. However most of them are complex, time-consuming. Herein, we report a novel method, which only need one conventional endonuclease (NEase) and achieve site-specific cleavage in a programmable way, to detect single base mismatch, termed aligner-mediated cleavage-based single base mismatch discrimination (AMCMD). The DNA aligner (DA) is in a stem-loop structure, consistent with an incomplete recognition site of NEase on its stem and a 5′-side arm complementary to the target sequence (TS). Once TS contains matched base and hybridizes with DA, the complete recognition site of NEase is formed, and the TS will be cleavaged with fast speed, while converse is not. Based on it, the method can clearly distinguish mismatched and complementary bases. Without sample pre-processing, we were able to obtain and verify all the test result in about 30 min through the polyacrylamide gel electrophoresis analysis. This endows the proposed method with a simpler advantage. Then we combined AMCMD and EXPAR to create a new method for single base mismatch discrimination, the short sequence obtained by AMCMD as a target to trigger EXPAR, with a detection limit at 1pM level. Another process with human serum underlines that AMCMD is compatible with the complex biological sample, thus it has the potentials for practical applications.

The controlled synthesis of metallic nanomaterials has attracted the interest of many researchers due to their shape-dependent physical and chemical properties. However, most of the synthesized nanocrystals cannot be combined with spectroscopy to measure the reaction kinetics, thus limiting their use in monitoring the catalytic reaction process to elucidate its mechanism. As a powerful analytical tool, surface-enhanced Raman spectroscopy (SERS) can be used to achieve in situ monitoring of catalytic reactions by developing bifunctional metal nanocrystals with both SERS and catalytic activities. Herein, we have developed a simple one-pot synthesis method for the large-scale and size-controllable preparation of highly rough hydrangea Au hollow nanoparticles. The growth mechanism of flower-like Au hollow nanostructures was also discussed. The hollow nanostructure with a 3D hierarchical flower shell combines the advantages of hollow nanostructure and hierarchical nanostructure, which possess high SERS activity and good catalytic activity simultaneously. Furthermore, the hydrangea Au hollow crystals were used as a bifunctional nanocatalyst for in situ monitoring of the reduction reaction of 4-nitrothiophenol to the 4-aminothiophenol.

Controllable preparation of nanocrystals (NCs) is a prerequisite to reveal their shape-dependent physicochemical properties. Herein, by using a one-pot synthesis method, ethylene glycol (EG) as a solvent and a reducing agent, poly(diallyldimethylammonium chloride) (PDDA) as a ligand, and AgNO3 as an additive, we successfully prepared octahedral, rhombic dodecahedral (RD), tetrahexahedral (THH) and truncated ditetragonal prism (TDP) Au NCs. And by simply tuning the reaction temperature and thus the reducing power of EG, we not only realized the shape transformation of Au NCs among low-index facet crystals ({111} to {110} facet) and low-index facet crystals to high-index facet crystals ({111} to {210} facet), but also achieved the shape evolution among high-index facet crystals ({210} to {310} facet). At a relatively high reaction temperature of 195 °C, (b.p. 198 °C) stepwise evolution of Au NCs from a {111}-bounded octahedron to a {210}-bounded THH and then to a {310}-bounded TDP was achieved. Furthermore, by simply reducing the reaction temperature to 160 °C, the {111}-bounded octahedral Au NCs would transform into RD Au NCs enclosed with the {110} facet. And the morphology evolution of Au crystals caused by different experimental parameters was systemically investigated. We found that the evolution of the crystal morphology is the result of the synergistic effect of the UPD effect of Ag0 and the oxidative etching of O2/Cl−. In addition, high-index facet THH Au NCs with controllable sizes of 65–120 nm were prepared by adjusting the amount of the PDDA solution added to the growth solution. This work not only provides a new method to synthesize Au NCs with tunable shape and size, but is also helpful in understanding the crystal growth habit.

Controllable morphological metal catalytic materials have always been a focus in research. In the previous work, hexapod AgCl was successfully synthesized. In this paper, hexapod Ag@AgCl microstructures with diverse Ag contents are prepared through NaBH4 reduction. They are characterized by scanning electron microscopy (SEM) and the element distribution is proved by an energy dispersive X-ray spectrometer (EDS). They are porous dendritic microstructures with a large specific surface area and a rough surface, which display high catalytic performance and surface-enhanced Raman spectroscopy (SERS) activity. Furthermore, the hexapod Ag@AgCl microstructure is devoted as a dual catalyst to monitor the reduction of 4-nitrothiophenol (4-NTP) to 4-aminothiophenol (4-ATP) in situ using SERS. Ultraviolet–visible (UV–Vis) spectroscopy was employed to evaluate the catalytic performance of the hexapod Ag@AgCl microstructures. The consequences show that the velocity of reaction became faster with a corresponding increase in silver content and the reaction mechanism was cleared. In addition to preparing a good catalyst, this work also promotes the combination of micro-nano materials and spectroscopy technology.

The multiply depolarized composite cathode consisted of Li1.2Mn0.54Ni0.13Co0.13O2 (LMNCO) and a combinatory conductive network of graphene (GN) + carbon nanotubes (CNTs) in the active material and GN coating at the interface of current collector is synthesized via pasting LMNCO/GN/CNTs composite slurry on GN coated Al foil. The interlaced GN + CNTs conductive network improves both the electronic conductivity and Li ion transport and stabilizes the structure of composite. The GN coating at the interface of current/active materials interlaces with GN + CNTs in the active materials and improves the adhesion and reduces the resistance between the active material and current collector. Consequently, the LMNCO composite cathode exhibits superior rate capacities of 132 mAh g−1 at 5C and 97 mAh g−1 at 10C, high cycling capacity retentions of 86% at 1C and 85% at 2C after 100 cycles, respectively and lower voltage fading. This combinatory conductive network is much more efficient for reducing the resistance and polarization of electrode than any single conductive network of GN + CNTs, CNTs, GN or GN coating.

Shape transformation of Au crystals from a {111}-bounded octahedron to a {730}-bounded tetrahexahedron (THH) and then to a {310}-bounded truncated ditetragonal prism (TDP) was achieved by a one pot synthesis method. The transformation of the crystal morphology is the result of the synergistic effect of Ag+ and O2/Cl-. This work not only provides a way to prepare high-index faceted Au micro/nanocrystals, but also provides new insights into the crystal growth habit.

In this work, we have synthesized hexapods AgCl crystals with mace pods for the first time. Diallyldimethylammonium chloride (DDA)-controlled stepwise evolution of AgCl crystals from octahedron to hexapods with mace pods are achieved by one-pot method. The intermediates have been captured which show the basic process of crystal growth. In this process, octahedra AgCl crystals firstly grow along the direction and then change to grow in the direction. At the same time, the size of AgCl grow from 2 μm to 20 μm. Due to the poor absorption of visible light by AgCl, sodium borohydride(NaBH4) is used to reduce AgCl hexapods with mace pods crystals. By changing the mole ratio(R) of NaBH4 to AgCl, the new structure was reduced to obtain a series of Ag@AgCl microstructures. Visible light catalysis effects of the Ag@AgCl microstructures on degradation of methyl orange (MO) were investigated. The Ag@AgCl microstructures with R = 0.02 have a high photocatalytic performance, which completely degrades MO in 40 minutes.

Calcium-looping technology has been identified as one of the most favorable CO2 capture techniques for the implementation of carbon capture, utilization, and storage (CCUS); however, the rapid deactivation of CaO sorbents due to sintering is currently a major barrier of this technology. We report for the first time an environmentally benign and cost-effective strategy to reduce sintering by adding waste-derived nanosilica, synthesized from photovoltaic waste (SiCl4), into Cao-based sorbents through a simple dry mixing procedure. The as-synthesized sorbent (90% CaCO3–W) resulted in final CO2 uptake of 0.32 g(CO2) g(CaO)−1 within 5 min of carbonation. Even under the most severe calcination conditions (at 920 °C in pure CO2), it still maintained a stable capture capacity, with CO2 uptake of 0.23 g(CO2) g(CaO)−1 after 30 cycles. Additionally, the CO2 uptake percentage reached ∼90% in the fast carbonation stage (∼20 s), which is of great significance for real applications. The most likely stabilization mechani...

The liquid phase oxidation of benzyl alcohol is an important reaction for generating benzaldehyde and benzoic acid that are largely required in the perfumery and pharmaceutical industries. The current production systems suffer from either low conversion or over oxidation. From the viewpoint of economy efficiency and environmental demand, we are aiming to develop new high-performance and cost-effective catalysts based on manganese oxides that can allow the green aerobic oxidation of benzyl alcohol under mild conditions. It was found that the composition of the precursors has significant influence on the structure formation and surface property of the manganese oxide nanoparticles. In addition, the crystallinity of the resulting manganese nanoparticles was gradually improved upon increasing the calcination temperature; however, the specific surface area decreased obviously due to pore structure damage at higher calcination temperature. The sample calcined at the optimal temperature of 600 °C from the precursors without porogen was a Mn3O4-rich material with a small amount of Mn2O3, which could generate a significant amount of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mathrm{O}}_2^{-} $$\end{document}O2- species on the surface that contributed to the high catalytic activity in the oxidation. Adding porogen with precursors during the synthesis, the obtained catalysts were mainly Mn2O3 crystalline, which showed relatively low activity in the oxidation. All prepared samples showed high selectivity for benzaldehyde and benzoic acid. The obtained catalysts are comparable to the commercial OMS-2 catalyst. The synthesis–structure–catalysis interaction has been addressed, which will help for the design of new high-performance selective oxidation catalysts. Electronic supplementary material The online version of this article (doi:10.1186/s11671-016-1777-y) contains supplementary material, which is available to authorized users.