Convenient generation of stable superatomic silver clusters and their systematic site-specific tailoring and directional assembly present an enduring and significant challenge. In this work, we ...prepared a face-centered cubic (fcc) array of Ag14 superatoms protected by face-capping 1,2-dithiolate-o-carborane (C2B10H10S2) ligands, each produced from 1-thiol-o-carborane in crystallization with simultaneous reduction of Ag+ to Ag0. We find that the corner N-donor ligands contribute predominately to the stability and luminescence of the Ag14 superatom. As the first-formed nanocluster Ag14(C2B10H10S2)6(CH3CN)8·4CH3CN (NC-1) with labile vertex-coordinated CH3CN ligands is highly unstable, monodendate pyridine ligands were used to replace these CH3CN species site-specifically, giving Ag14(C2B10H10S2)6(pyridine/p-methylpyridine)8 (NCs-2,3) in gram scale with its core structure intact, which features ultrastability up to 150 °C in air. Moreover, using bidentate N-containing ligands to bridge the superatomic Ag14 building blocks, we constructed an unprecedented hierarchical series of 1D-to-3D superatomic silver cluster-assembled materials (SCAM-1,2,3,4), and SCAM-4 is air-stable up to 220 °C. Furthermore, this series of stable solid-state superatomic-nanocluster materials exhibit tunable dual emission with wide-range thermochromism. The present study constitutes a major step toward the development of ligand-modulation of the structure, stability, assembly, and functionality of superatomic silver nanoclusters.
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IJS, KILJ, NUK, PNG, UL, UM
Gold nanoclusters have become promising radiosensitizers due to their ultrasmall size and robust ability to adsorb, scatter, and re-emit radiation. However, most of the previously reported gold ...nanocluster radiosensitizers do not have a precise atomic structure, causing difficulties in understanding the structure–activity relationship. In this study, a structurally defined gold–levonorgestrel nanocluster consisting of Au8(C21H27O2)8 (Au8NC) with bright luminescence (58.7% quantum yield) and satisfactory biocompatibility was demonstrated as a nanoradiosensitizer. When the Au8NCs were irradiated with X-rays, they produced reactive oxygen species (ROS), resulting in irreversible cell apoptosis. As indicated by in vivo tumor formation experiments, tumorigenicity was significantly suppressed after one radiotherapy treatment with the Au8NCs. In addition, compared with tumors treated with X-rays (4 Gy) alone, tumors treated with the nanosensitizer exhibited an inhibition rate of 74.2%. This study contributes to the development of atomically precise gold nanoclusters as efficient radiosensitizers.
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IJS, KILJ, NUK, PNG, UL, UM
Doping of polymeric semiconductors limits the miscibility between polymers and dopants. Although significant efforts have been devoted to enhancing miscibility through chemical modification, the ...electrical conductivities of n‐doped polymeric semiconductors are usually below 10 S cm−1. We report a different approach to overcome the miscibility issue by modulating the solution‐state aggregates of conjugated polymers. We found that the solution‐state aggregates of conjugated polymers not only changed with solvent and temperature but also changed with solution aging time. Modulating the solution‐state polymer aggregates can directly influence their solid‐state microstructures and miscibility with dopants. As a result, both high doping efficiency and high charge‐carrier mobility were simultaneously obtained. The n‐doped electrical conductivity of P(PzDPP‐CT2) can be tuned up to 32.1 S cm−1. This method can also be used to improve the doping efficiency of other polymer systems (e.g. N2200) with different aggregation tendencies and behaviors.
The dynamic behaviors of conjugated polymer aggregates in solution are correlated with the solid‐state doping efficiency of polymer films. The n‐type electrical conductivity of the polymer P(PzDPP‐CT2) can be significantly enhanced by controlling the dynamics of solution‐state aggregates. The method is general and can be used for other polymer systems with different aggregation tendencies and dynamic behaviors.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Benzylamine is introduced as a surface passivation molecule that improves the moisture‐resistance of the perovskites while simultaneously enhancing their electronic properties. Solar cells based on ...benzylamine‐modified formamidinium lead iodide perovskite films exhibit a champion efficiency of 19.2% and an open‐circuit voltage of 1.12 V. The modified FAPbI3 films exhibit no degradation after >2800 h air exposure.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Doping has been widely used to control the charge carrier concentration in organic semiconductors. However, in conjugated polymers, n-doping is often limited by the tradeoff between doping ...efficiency and charge carrier mobilities, since dopants often randomly distribute within polymers, leading to significant structural and energetic disorder. Here, we screen a large number of polymer building block combinations and explore the possibility of designing n-type conjugated polymers with good tolerance to dopant-induced disorder. We show that a carefully designed conjugated polymer with a single dominant planar backbone conformation, high torsional barrier at each dihedral angle, and zigzag backbone curvature is highly dopable and can tolerate dopant-induced disorder. With these features, the designed diketopyrrolopyrrole (DPP)-based polymer can be efficiently n-doped and exhibit high n-type electrical conductivities over 120 S cm
−1
, much higher than the reference polymers with similar chemical structures. This work provides a polymer design concept for highly dopable and highly conductive polymeric semiconductors.
The basic helix-loop-helix (bHLH) proteins, a large transcription factors family, are involved in plant growth and development, and defensive response to various environmental stresses. The ...resurrection plant Myrothamnus flabellifolia is known for its extremely strong drought tolerance, but few bHLHs taking part in abiotic stress response have been unveiled in M. flabellifolia.
In the present research, we cloned and characterized a dehydration-inducible gene, MfbHLH38, from M. flabellifolia. The MfbHLH38 protein is localized in the nucleus, where it may act as a transcription factor. Heterologous expression of MfbHLH38 in Arabidopsis improved the tolerance to drought and salinity stresses, as determined by the studies on physiological indexes, such as contents of chlorophyll, malondialdehyde (MDA), proline (Pro), soluble protein, and soluble sugar, water loss rate of detached leaves, reactive oxygen species (ROS) accumulation, as well as antioxidant enzyme activities. Besides, MfbHLH38 overexpression increased the sensitivity of stomatal closure to mannitol and abscisic acid (ABA), improved ABA level under drought stress, and elevated the expression of genes associated with ABA biosynthesis and ABA responding, sucha as NCED3, P5CS, and RD29A.
Our results presented evidence that MfbHLH38 enhanced tolerance to drought and salinity stresses in Arabidopsis through increasing water retention ability, regulating osmotic balance, decreasing stress-induced oxidation damage, and possibly participated in ABA-dependent stress-responding pathway.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A structure-determined gold-levonorgestrel nanocluster, Au
10
(C
21
H
27
O
2
)
10
(Au
10
NC), has been obtained
via
solvent induced crystal transformation from Au
8
(C
21
H
27
O
2
)
8
(Au
8
NC), ...accompanied by a fluorescence color change from green to yellow. A cationic polymer, poly(allylamine hydrochloride) (PAH), was chosen to assemble with Au
10
NC to prepare monodisperse and stable particles (Au
10
NC-PAH) with an increased quantum yield of 49.8%. The as-fabricated Au
10
NC-PAH realized effective antibody-mediated actin imaging and sustained drug release.
The fluorescent properties of atomically precise nanoclusters have been regulated by solvent-induced atomic structure transformation and cationic polymer-induced self-assembly for cell imaging and drug delivery.
Diabetes has become one of the most prevalent endocrine and metabolic diseases that threaten human health, and it is accompanied by serious complications. Therefore, it is vital and pressing to ...develop novel strategies or tools for prewarning and therapy of diabetes and its complications. Fluorescent probes have been widely applied in the detection of diabetes due to the fact of their attractive advantages. In this report, we comprehensively summarize the recent progress and development of fluorescent probes in detecting the changes in the various biomolecules in diabetes and its complications. We also discuss the design of fluorescent probes for monitoring diabetes in detail. We expect this review will provide new ideas for the development of fluorescent probes suitable for the prewarning and therapy of diabetes in future clinical transformation and application.
The simplicity of the green-synthesized routine and the availability of surface modification of diverse bioactive molecules make noble metal nanostructures highly suitable as multifunctional ...biomaterials for biological and biomedical application. Here, we report the preparation of trypsin stabilized gold nanoclusters (try-AuNCs) with near-infrared fluorescence for biosensing heparin based on surface plasmon enhanced energy transfer (SPEET) and folic acid (FA) modified try-AuNCs for in vivo cancer bioimaging. The SPEET/try-AuNCs fluorescence biosensor was designed via heparin mediated energy transfer between try-AuNCs and cysteamine modified gold nanoparticles (cyst-AuNPs). The developed SPEET/try-AuNCs fluorescence biosensor allowed sensitive and selective detection of heparin with a linear range of 0.1–4.0 μg mL–1 and a detection limit (3s) of 0.05 μg mL–1. The relative standard deviation for eleven replicate detections of 2.5 μg mL–1 heparin was 1.1%, and the recoveries of the spiked heparin in human serum samples ranged from 97% to 100%. In addition, folic acid was immobilized on the surface of try-AuNCs to ameliorate the specific affinity of AuNCs for tumors, and the near-infrared fluorescent FA-try-AuNCs were applied for in vivo cancer imaging of high folate receptor (FR) expressing Hela tumor. In vivo study of the dynamic behavior and targeting ability of FA-try-AuNCs probe to Hela tumor bearing mice and normal nude mice validated the high specific affinity of FA-try-AuNCs probe to FR positive tumors. The results show that the prepared try-AuNCs have great potential as multifunctional biomaterials for biosensing biomolecules with SPEET mode and in vivo cancer imaging with high targeting ability.
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IJS, KILJ, NUK, PNG, UL, UM
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•A colorimetric fluorescent probe was designed and synthesized for the detection of bisulfite with high sensitivity and selectivity in 100% aqueous solution.•The probe has been ...successfully used for the detection of SO2 in food and animal serum samples with good recovery.•The probe was used as a solid sensor to visually detect the liquid and gas sulfur dioxide on the test strips.•The probe could detect both bisulfite in food and gaseous SO2 in the environment.
Bisulfite (HSO3−) has the functions of bleaching, antiseptic, antioxidant, inhibiting bacterial growth, and controlling enzymatic reactions in food. However, long-term consumption of foods containing excessive amounts of bisulfite can be harmful to health. In addition, large doses of sulfur dioxide (SO2) can cause diarrhea, hypotension, allergic and asthmatic reactions in susceptible individuals. Therefore, it is urgent and essential to explore some rapid, reliable, and convenient tools to detect HSO3− in food and SO2 gas. Herein, we exploited a fluorescent probe, NPO, to detect HSO3− in 100 % aqueous solution. The probe has the advantages of easy synthesis, excellent water solubility, significant colorimetric change, good selectivity, high sensitivity, and fast response (within 1 min). Probe NPO was successfully applied for testing strips to visualize the behavior of HSO3− and SO2 gas. Moreover, the probe has been used to monitor the behavior of HSO3− in real food samples and animal serum samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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