ZnS/SnS2 Heterostructures Encapsulated in N-Doped Carbon Nanofibers for High-Performance Alkali Metal-Ion Batteries.

Heterogeneous composite ZnS/SnS2 is designed to meet various requirements for alkali metal-ion batteries. The composite is prepared using an electrostatic spinning method and encapsulated in N-doped carbon fibers after high-temperature vulcanization. The special structure of the composite provides a dependable interconnection and fast conductive network for alkali metal ions. The conductive carbon network shortens the diffusion path and greatly improves the migration efficiency of the alkali metal ions in the electrode. As expected, when the current density is 0.1 A g-1, the ZnS/SnS2@NCNFs maintain a high discharge capacity of more than 1437.5, 1321.2, and 861.6 mA h g-1 for lithium-ion, sodium-ion, and potassium-ion batteries, respectively. What is more, a full cell using a prelithiated composite anode and a LiFePO4 cathode is tested and shows excellent electrochemical performance. This work provides new perspectives for the development of novel anodes that can efficiently store alkali metal ions, as well as for the fine-structure design of materials.

Comparison of Reductive Ligation-Based Detection Strategies for Nitroxyl (HNO) and S-Nitrosothiols.

Invited for this month's cover picture is the group of Prof. S. Bruce King at the Department of Chemistry of Wake Forest University. The cover picture shows a prefluorescent phosphine-based probe reacting with nitroxyl (HNO) and S -nitrosothiol (RSNO), nitrogen oxide-derived biological signals. Both species react with the prefluorescent probe, but only the product from the HNO reaction can complete a further chemical ligation pathway that results in fluorescence, indicating the presence of HNO. The product of the probe with RSNO does not complete this ligation and does not generate a fluorescent species. These phosphine-based probes thus demonstrate a selectivity for HNO over RSNO based on their chemical reactivity and can be used in biological systems to differentiate these species. For more details, see the Communication on p. 110 ff. Read the full text of the article at 10.1002/open.201500200.

Comparison of Reductive Ligation-Based Detection Strategies for Nitroxyl (HNO) and S-Nitrosothiols.

Phosphine-based detection strategies for both nitroxyl (HNO) and S-nitrosothiols (RSNO) were investigated and compared. Phosphorus NMR studies show that azaylides derived from HNO or organic RSNO efficiently participate in subsequent reductive ligation required for fluorescence generation in properly substituted substrates. S-Azaylides derived from biological RSNO containing free amine and carboxylic acid groups primarily yield phosphine oxides suggesting these groups facilitate nonligation pathways such as hydrolysis. The fluorescence response of a phosphine-based fluorophore toward the same RSNO confirms these differences and indicates that these probes selectively react with HNO. Flow cytometry experiments in HeLa cells reinforce the reactivity difference and offer a potential fast screening approach for endogenous HNO sources.

Recent advances in the chemical biology of nitroxyl (HNO) detection and generation.

Nitroxyl or azanone (HNO) represents the redox-related (one electron reduced and protonated) relative of the well-known biological signaling molecule nitric oxide (NO). Despite the close structural similarity to NO, defined biological roles and endogenous formation of HNO remain unclear due to the high reactivity of HNO with itself, soft nucleophiles and transition metals. While significant work has been accomplished in terms of the physiology, biology and chemistry of HNO, important and clarifying work regarding HNO detection and formation has occurred within the last 10 years. This review summarizes advances in the areas of HNO detection and donation and their application to normal and pathological biology. Such chemical biological tools allow a deeper understanding of biological HNO formation and the role that HNO plays in a variety of physiological systems.

A selective phosphine-based fluorescent probe for nitroxyl in living cells.

A novel fluorescein-based fluorescent probe for nitroxyl (HNO) based on the reductive Staudinger ligation of HNO with an aromatic phosphine was prepared. This probe reacts with HNO derived from Angeli's salt and 4-bromo Piloty's acid under physiological conditions without interference by other biological redox species. Confocal microscopy demonstrates this probe detects HNO by fluorescence in HeLa cells and mass spectrometric analysis of cell lysates confirms this probe detects HNO following the proposed mechanism.

A reductive ligation based fluorescent probe for S-nitrosothiols.

A reductive ligation based fluorescent probe () for the detection of S-nitrosothiols (SNO) was developed. The probe showed good selectivity and sensitivity for SNO.

Facile synthesis of spiroisoquinolines based on photocycloaddition of isoquinoline-1,3,4-trione with oxazoles.

Photocycloaddition of isoquinoline-1,3,4-trione and 5-methoxyoxazoles affords spiroisoquinolineoxetanes with high regio- and diastereoselectivity. The spiroisoquinolineoxetanes can be conveniently converted into novel spiroisoquinolineoxazoline derivatives through acid catalyzed sequential reactions.

Preparation of quantum dot bioconjugates and their applications in bio-imaging.

Quantum dots (QDs) are new generation of fluorophores with superior optical properties. For biological applications of QDs, proper surface modification and further conjugation with biomolecules are necessary to make these nanocrystals biocompatible as well as target-recognizable. Preparation of QDs bioconjugates was reviewed in this paper to demonstrate general strategies in the bioconjugation of QDs and typical QDs bioconjugates including QDs conjugated with peptides, proteins or oligonucleotides were introduced. Recent examples on the applications of QDs bioconjugates for sensitive detection of biomolecules such as nucleic acids or proteins were reviewed. QDs bioconjugates used in cell labeling and trafficking, in detection of subcellular molecules and in imaging protein dynamics in live cells were also reviewed with an emphasis on current work reported in the past two years. Latest progress on the application of QDs bioconjugates for in vivo imaging was briefly covered and perspective on QDs bioconjugates and their applications in bio-imaging was discussed with related to the issues to be addressed in future QDs applications.