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The exploration of the physical attributes of the recently discovered orthocarbonate Sr3CO5 is significant for comprehending the carbon cycle and storage mechanisms within the Earth's interior. In this study, first-principles calculations are initially used to examine the structural phase transitions of Sr3CO5 polymorphs within the range of lower mantle pressures. The results suggest that Sr3CO5 with the Cmcm phase exhibits a minimal enthalpy between 8.3 and 30.3 GPa. As the pressure exceeds 30.3 GPa, the Cmcm phase undergoes a transition to the I4/mcm phase, while the experimentally observed Pnma phase remains metastable under our studied pressure. Furthermore, the structural data of SrO, SrCO3, and Sr3CO5 polymorphs are utilized to develop a deep learning potential model suitable for the Sr–C–O system, and the pressure–volume relationship and elastic constants calculated using the potential model are in line with the available results. Subsequently, the elastic properties of Cmcm and I4/mcm phases in Sr3CO5 at high temperature and pressure are calculated using the molecular dynamics method. The results indicate that the I4/mcm phase exhibits higher temperature sensitivity in terms of elastic moduli and wave velocities compared to the Cmcm phase. Finally, the thermodynamic properties of the Cmcm and I4/mcm phases are predicted in the range of 0–2000 K and 10–120 GPa, revealing that the heat capacity and bulk thermal expansion coefficient of both phases increase with temperature, with the constant volume heat capacity gradually approaching the Dulong–Petit limit as the temperature rises. [ABSTRACT FROM AUTHOR]

Copper hydrides are very useful in hydrogenation reactions. We report a stable Stryker-type copper hydride reagent protected by hemilabile phosphines: [Cu8H6(dppy)6](OTf)2 (Cu8-H, dppy = diphenylphosphino-2-pyridine). The metal core of this cluster has a bicapped octahedral configuration, and the copper-bound hydrides each triply bridges over a triangular face of the octahedron. This cluster is attractive due to its facile preparation and excellent stability under ambient conditions. The comparable activity and selectivity both in the stoichiometric and catalytic reactions make Cu8-H a promising alternative to Stryker's reagent. [ABSTRACT FROM AUTHOR]

Herein, an anionic metal–organic framework, formulated as {[Zn3(OH)(bmipia)(H2O)3]4·[Zn(H2O)6.5]2}n (FCS-3), was prepared from zinc ions and semi-rigid carboxylate ligands of 5-[N,N-bis(5-methylisophthalic acid)amion] isophthalic acid (H6bmipia) and was employed as a unique fluorescence turn-on chemical sensor for the ultra-sensitive detection of various antibiotics in the aqueous phase. [ABSTRACT FROM AUTHOR]

The identification of hydride(s) in gold nanoclusters is a challenging task, due to the instability of gold nanoclusters containing hydrides. Herein, we report two ultrastable hydrido gold nanoclusters protected by phosphine ligands: [Au20(PPh3)12H3](SbF6)3 (1H) and [Au20(PPh3)12H2(2-COOH-PhS)](PF6)3 (2H). The presence of hydrides in gold(0)–gold(I) nanoclusters is clearly demonstrated by ESI mass spectrometry and NMR spectroscopy. Single crystal structural determination reveals that both nanoclusters have an unprecedented Au20 core consisting of a Au9 unit and a Au11 unit. Such cores derived from the connection of different basic units are important for understanding the evolution and stability of metal nanoclusters. The hydride (H−) was also verified by a charge distribution calculation. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinases (MMPs) are closely associated with various physiological and pathological processes, and have been regarded as potential biomarkers for severe diseases including cancer. Accurate determination of MMPs would advance our understanding of their roles in disease progression, and is of great significance for disease diagnosis, treatment and prognosis. In this review, we present a comprehensive overview of the developed bioassays/biosensors for detection of MMPs, and highlight the recent advancement in nanomaterial-based immunoassays for MMP abundance measurements and nanomaterial-based biosensors for MMP activity determination. Enzyme-linked immunosorbent assay (ELISA)-based immunoassays provide information about total levels of MMPs with high specificity and sensitivity, while target-based biosensors measure the amounts of active MMPs, and allow imaging of MMP activities in vivo. For multiplex and high-throughput analysis of MMPs, microfluidics and microarray-based assays are described. Additionally, we put forward the existing challenges and future prospects from our perspective. [ABSTRACT FROM AUTHOR]

Conducting polymer (CP)-based pseudocapacitive electrodes with good capacitance/rate capabilities and high potential window retention (namely, a neglectable IR drop) under high current density are of great interest due to their practical applications in fabricating instantaneous and high-power energy devices. However, they remain a challenge to realize. Herein, we report an alternative route for enhancing the capacitive properties of polypyrrole nanofibrous membrane (PPy NM)-based electrodes without adding any capacitive materials. The new strategy involves doping with Au nanoparticles via electrospinning followed by in situ polymerization. Compared with a pristine PPy NM, the specific capacitance of the Au/PPy NM was enhanced from 193.7 to 455.3 F g−1 at a scan rate of 5 mV s−1. Additionally, the rate capabilities were enhanced over broad ranges of current density (0.5–30 A g−1) and scan rate (5–1000 mV s−1). Interestingly, the potential window retention was greatly enhanced from 74.5% (PPy NM) to 95.6% (Au/PPy NM) over a wide range of current densities (0.5–30 A g−1). The Au/PPy NM also exhibited good cycling stability (>85% over 10 000 charge–discharge cycles under a current density of 30 A g−1). [ABSTRACT FROM AUTHOR]

We report a series of Ag–S nanoscale clusters in an attempt to understand the growth process of Ag2S clusters. UV-vis monitoring and crystallization at different stages of the reaction map out the cluster growth steps from Ag31S3(StBu)17(tfa)8(MeCN)4 (tfa = trifluoroacetate), to Ag45S7(StBu)24(tfa)7 to [Ag62S13(StBu)32(tfa)2](tfa)2, showing sequential eye-catching color changes. The cluster growth is associated with the in situ generation of S2−, which comes from the C–S bond cleavage of tert-butyl thiolate. [ABSTRACT FROM AUTHOR]

The addition of a non-adsorbing homopolymer to a block copolymer solution provides a convenient strategy for regulating its self-assembly. We systematically investigate the depletion effect from a homopolymer on the morphologies of AB diblock and BAB triblock copolymers in selective solvents. Increasing the homopolymer content results in larger spherical micelles, and the curvature of micelles is proportional to the square of homopolymer concentrations. A high enough homopolymer concentration may transfer micelles into vesicles. A deep analysis shows that the depletion effect produces attractive interaction between hydrophilic B blocks as well as their contraction on the micellar surface. The size of triblock copolymer micelles is not affected by homopolymers significantly, and spherical-to-wormlike micelle transition occurs at high homopolymer contents. These results have important applications for the precise design of self-assembled nanostructures of copolymer systems. [ABSTRACT FROM AUTHOR]

Gold(i) phosphinopyridyl clusters [Au9(PNC)6](BF4)3 (1) and [Au11(PNC)6(PPh3)2](BF4)5 (2) (PNC = 2-diphenylphosphinopyridyl monoion) are assembled. In contrast to the green luminescence of 1, 2 is brightly orange emissive in CH2Cl2, which shows the presence of unsupported AuI–AuI interactions in solution. Besides, 1 and 2 can selectively light up the mitochondria of living cells. [ABSTRACT FROM AUTHOR]

Heteroatomic conjugated polymers (HCPs) can have complicated molecular structures with several heteroatoms in the repeat unit, which is helpful for designing color-tunable emitters, photovoltaic donors and high mobility materials. In order to understand their relatively complex molecular superstructure characteristics in depth, heteroatomic substitution-induced diverse non-covalent interactions must be investigated. Here, we systematically studied the gelation processing and its influence on the optoelectronic properties of a series of sp2 nitrogen (N) substituted polyfluorenes (PF8-co-DAF8) towards highly stable blue polymer light-emitting diodes (PLEDs). This heteroatomic substitution allows for diverse chain C–H…N hydrogen bonds, correlating with an excellent gelation behavior at room temperature. Films with a gelation superstructure show a weak interchain π–π interaction and energy transfer compared to non-gelation ones. PLEDs based on a gelation film give a stable, deep-blue emission with CIE coordinates of (0.16, 0.17) and a luminous efficiency (L.E.) of 1.30 cd A−1, while non-gelation film-based PLEDs display a stable, sky-blue emission (CIE: 0.20, 0.24; L.E.: 2.13 cd A−1). Diverse non-covalent interactions originating from the heteroatomic substitution cause a complicated molecular aggregation behavior in solution that can significantly affect the chain rearrangement in the film-casting process, thereby dominating the optoelectrical properties. [ABSTRACT FROM AUTHOR]

Ligand-protected metal nanoclusters as unique nanomaterials have attracted great attention. The protecting ligands that directly bind on the cluster surfaces are crucial in dictating the structures and properties of the clusters. In contrast to the extensively studied thiolates, alkynyl ligands have been found recently to be important ligands for passivating gold/silver cluster surfaces. In this Frontier article, recent advances in alkynyl-protected metal nanoclusters are overviewed, and the structures, luminescence and catalytic activities are also discussed. It is demonstrated that alkynyls are very promising ligands in the control of the structures and properties of gold/silver nanoclusters. [ABSTRACT FROM AUTHOR]

A gold(i)–silver(i) cluster bearing six carboxylate groups has been synthesized through the oxidation of its aldehyde precursor and the Au6 core of this cluster displays an octahedral or a trigonal prismatic configuration depending on the crystallization conditions. The reversible interconversion between these two isomers can be triggered in the solid state by the addition or removal of acetonitrile solvent molecules. Interestingly, luminescence changes were observed as each configuration shows different emission colors, yellow for octahedral type and red for the trigonal prismatic one. [ABSTRACT FROM AUTHOR]

DNA methylation is a crucial epigenetic modification and is closely related to tumorigenesis. Herein, a surface ligation-based high throughput method combined with bisulfite treatment is developed for analysis of methylated genomic DNA. In this method, a DNA microarray is employed as a reaction platform, and resonance light scattering (RLS) of nanoparticles is used as the detection principle. The specificity stems from allele-specific ligation of Taq DNA ligase, which is further enhanced by improving the fidelity of Taq DNA ligase in a heterogeneous reaction. Two amplification techniques, rolling circle amplification (RCA) and silver enhancement, are employed after the ligation reaction and a gold nanoparticle (GNP) labeling procedure is used to amplify the signal. As little as 0.01% methylated DNA (i.e. 2 pmol L−1) can be distinguished from the cocktail of methylated and unmethylated DNA by the proposed method. More importantly, this method shows good accuracy and sensitivity in profiling the methylation level of genomic DNA of three selected colonic cancer cell lines. This strategy provides a high throughput alternative with reasonable sensitivity and resolution for cancer study and diagnosis. [ABSTRACT FROM AUTHOR]

The mapping of specific single nucleotide polymorphisms (SNPs) in patients’ genome is a critical process for the development of personalized therapy. In this work, a DNA microarray-based resonance light scattering (RLS) assay has been developed for multiplexed detection of breast cancer related SNPs with high sensitivity and selectivity. After hybridization of the desired target single-stranded DNAs (ssDNAs) with the ssDNA probes on a microarray, the polyvalent ssDNA modified 13 nm gold nanoparticles (GNPs) are employed to label the hybridization reaction through the formation of a three-stranded DNA system. The H2O2-mediated enlargement of GNPs is then used to enhance the RLS signal. The microarray-based RLS assay provides a detection limit of 10 pM (S/N = 3) for the target ssDNA and determines an allele frequency as low as 1.0% in the target ssDNA cocktail. Combined with an asymmetric PCR technique, the proposed assay shows good accuracy and sensitivity in profiling 4 SNPs related to breast cancer of three selected cell lines. [ABSTRACT FROM AUTHOR]

Combining 2-formylphenylboronic acid with 4-hydrazinylbenzoic acid in neutral aqueous solution at low, equimolar concentrations of the reagents results in a single, stable product, a 1,2-dihydro-1-hydroxy-2,3,1-benzodiazaborine, in a matter of minutes with no side products. Application of this reaction to protein conjugation demonstrates that the reaction is orthogonal to protein functional groups, and the resulting conjugate withstands SDS-PAGE analysis. This reaction should be particularly useful for couplings that must be performed with low concentrations of reagents under physiologically compatible conditions. [ABSTRACT FROM AUTHOR]

The exploration of the physical attributes of the recently discovered orthocarbonate Sr 3 CO 5 is significant for comprehending the carbon cycle and storage mechanisms within the Earth's interior. In this study, first-principles calculations are initially used to examine the structural phase transitions of Sr 3 CO 5 polymorphs within the range of lower mantle pressures. The results suggest that Sr 3 CO 5 with the Cmcm phase exhibits a minimal enthalpy between 8.3 and 30.3 GPa. As the pressure exceeds 30.3 GPa, the Cmcm phase undergoes a transition to the I 4/ mcm phase, while the experimentally observed Pnma phase remains metastable under our studied pressure. Furthermore, the structural data of SrO, SrCO 3 , and Sr 3 CO 5 polymorphs are utilized to develop a deep learning potential model suitable for the Sr-C-O system, and the pressure-volume relationship and elastic constants calculated using the potential model are in line with the available results. Subsequently, the elastic properties of Cmcm and I 4/ mcm phases in Sr 3 CO 5 at high temperature and pressure are calculated using the molecular dynamics method. The results indicate that the I 4/ mcm phase exhibits higher temperature sensitivity in terms of elastic moduli and wave velocities compared to the Cmcm phase. Finally, the thermodynamic properties of the Cmcm and I 4/ mcm phases are predicted in the range of 0-2000 K and 10-120 GPa, revealing that the heat capacity and bulk thermal expansion coefficient of both phases increase with temperature, with the constant volume heat capacity gradually approaching the Dulong-Petit limit as the temperature rises.

An efficient N-centered radical intramolecular cyclization reaction of alkenyl amides induced by visible light was described. In this process, an alkenyl amide underwent 5-exo / 6-endo cyclization to selectively yield two critical alkaloid structures, namely isoindolinones and isoquinolinones.

The one-pot two-step intramolecular aryl and heteroaryl C-H trifluoromethoxylation recently reported by our group has provided a general, scalable, and operationally simple approach to access a wide range of unprecedented and valuable OCF3-containing building blocks. Herein we describe our investigations to elucidate its reaction mechanism. Experimental data indicate that the O-trifluoromethylation of N-(hetero)aryl-N-hydroxylamine derivatives is a radical process, whereas the OCF3-migration step proceeds via a heterolytic cleavage of the N-OCF3 bond followed by rapid recombination of a short-lived ion pair. Computational studies further support the proposed ion pair reaction pathway for the OCF3-migration process. We hope that the current study would provide useful insights for the development of new transformations using versatile N-(hetero)aryl-N-hydroxylamine synthons.