Latest ArticlesAcenapththylene-imide (AnI), similar to naphthalene diimide (NDI), is an outstanding building block for organic functional materials and has gained a lot of research attention. Herein, Sulphur and Selenium-embedded AnI-containing polycyclic aromatic hydrocarbon molecules, AnI-SQ and AnI-SeQ, with [1, 2, 5]thiadiazolo [3, 4-g]quinoxaline (SQ) and [1, 2, 5]selenadiazolo [3, 4-g]quinoxaline (SeQ) are designed and synthesized with low-lying LUMO energy levels. The absorption and emission of AnI-SQ and AnI-SeQ displayed a bathochromic shift upon protonation of the C = N bond. Besides, theoretical calculation indicates remarkable rigid planar backbones for both AnI-SQ and AnI-SeQ. Through self-assembly with polymeric Pluronic® F-127, corresponding hydrophilic nanoparticles (NPs) were prepared with low cytotoxicity. And AnI-SQ NPs could be applied for in vitro two-photon fluorescence imaging.
We have developed a metal-free radical cascade reaction of N-substituted 2-aryl indoles with readily available sulfonyl hydrazides for the rapid construction of arylsulfonyl-substituted indolo[2,1-a]isoquinolin-6(5H)-one derivatives. With the TBAI–TBHP catalytic system, a broad series of structurally diverse indolo[2,1-a]isoquinolin-6(5H)-one derivatives were obtained in moderate to excellent yields. The reaction features mild reaction conditions, operationally easiness, scaled-up feasibility, and high functional-group-tolerance.
We describe a janusarene derivative PyJ, which forms micrometer-scale one-dimensional metallo-supramolecular polymer through coordination driven self-assembly. PyJ is a well-preorganized dodecatopic pyridyl ligand built on a hexaphenylbenzene platform. The two-face structural feature of PyJ allows for a delicate control over multiple Py-Ag+-Py coordination interactions, leading to assembled structure of PyJ-Ag, which was characterized by dynamic light scattering, atomic force microscopy, and transmission electron microscopy.
Based on the host-guest molecular recognition capability of cucurbit[6]uril (CB[6]) modified on the gold surface, sensitive spectrophotometric and electrochemical methods for the detection of metformin (MET) have been developed. The molecular recognition between cucurbit[7]uril (CB[7]) or CB[6] and MET is initially demonstrated and the related recognition mechanism is further deliberated. First, CB[6]-modified gold nanoparticles (AuNPs/CB[6]) were synthesized and then characterized by ultraviolet visible light spectrum (UV–vis) and transmission electron microscopy (TEM). The aggregation of AuNPs/CB[6] prompted by MET triggered changes of color and the absorption spectrum, that explored for the visual identification and spectrophotometric determination of MET. Under the optimized detection conditions, the UV–vis spectrometry had a good linear relationship in the range of 6–700 µmol/L, and the detection limit was 2 µmol/L. In addition, a single-layer CB[6]-modified gold electrode (GE-CB[6]) detection system for MET was constructed. As the concentration of MET in the solution continues to increase, the charge transfer resistance (Rct) in the Nyquist diagram of the electrochemical impedance method (EIS) continues to increase. In the concentration range from 10 pmol/L to 20 nmol/L, the logarithm of the MET concentration has a good linear relationship with Rct, and the detection limit of this method is 1.35 pmol/L. Both methods have good concentration sensitivity to MET in different concentration ranges, providing a powerful tool for the detection of MET.
A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described. The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond. Under acidic conditions, sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations. While under alkaline conditions, cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently. The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.
MoS2 nanosheets (NSs) are novel 2D nanomaterials (NMs) with potential uses in many areas, and therefore oral exposure route to MoS2 NSs is plausible. Currently, MoS2 NSs are considered as biocompatible NMs, but there is lacking of systemic investigations to study the interactions of MoS2 NSs with intestinal cells. In this study, we exposed the 3D Caco-2 spheroids to MoS2 NSs or MoS2 powders (denoted as MoS2-bulk), and investigated the potential adverse effects of MoS2-materials based on transcriptomics and lipidomics analysis. As expected, both MoS2 NSs and MoS2-bulk were dose-dependently internalized into 3D Caco-2 spheroids but did not induce cytotoxicity, membrane disruption or decrease of thiols. However, the Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis indicated that nutrient absorption and metabolism was decreased. One of the most significantly decreased KEGG pathways is fat digestion and absorption (map04975), and Western blotting analysis further showed that fatty acid binding protein 1 and apolipoprotein A1, key proteins involved in fat digestion and absorption, were down-regulated by MoS2 NSs or MoS2-bulk. In addition, BODIPY 493/503 staining suggested that exposure to MoS2 NSs and MoS2-bulk decreased lipid levels in the spheroids. However, lipidomics data indicated that MoS2 materials only decreased 8 lipid classes, including lysophosphatidylcholine, lysodimethylphosphatidylethanolamine, N-acylethanolamine, ceramide phosphoethanolamines, gangliosides, lysosphingomyelin and sulfatide, whereas most of the lipid classes were indeed increased. In addition, MoS2 NSs was more potent to decrease the lipid classes compared with MoS2-bulk. Combined, the results from this study showed that MoS2 NSs and bulk materials were non-cytotoxic but altered lipid profiles in 3D Caco-2 spheroids.
White-light-emitting diodes (WLEDs) possess many merits, such as high efficiency and stability. Developing cost-effective, environmentally friendly, high-performance luminophores to achieve high-quality, full-spectrum, white lighting is of great importance to the construction and progress of WLEDs. In this work, solid-state, highly luminescent orange-emitting nanoclusters (MgCl2-Lys-Ag/Au NCs) were prepared via the salt-induced precipitation of Lys-Ag/Au NCs from solution, which showed a high absolute quantum yield of 44.5%. A cyan-emitting metal-organic framework (MOF)-like nanomaterial (named Fe@TAOH) was also prepared by the self-assembly of the coordination compound of Fe3+ and TAOH acted upon by H3PO4 via H-bonding and π-π stacking interactions, which showed an emission peak at 485 nm and an absolute quantum yield of 21.7%. The potential application of the two facile-synthesis, low toxicity, and highly luminescent materials in WLEDs was investigated. The WLEDs was constructed by coating powdered Fe@TAOH and MgCl2-Lys-Ag/Au NCs samples on commercial GaN LED chip with 365 nm emissions, and it exhibited acceptable white light characteristics with a CIE color coordinates and a color rendering index (CRI) of (0.28, 0.34) and 79.6, respectively, implying good prospects in the field of WLEDs.
Valuable application prospects and large-scale production technologies are powerful driving forces for the development of materials science. Carbon dots (CDs) are a kind of promising carbon-based fluorescent nanomaterials, which possess wide application prospects based and even beyond the fluorescence properties. Herein, we report the fast and high-yield synthesis of CDs and the large-scale preparation of fluorescent nanofiber films with enhanced mechanical properties. CDs were prepared from magnetic hyperthermia treatment of citric acid and carbamide, with the output of 25.37 g in a single batch. The as-prepared CDs exhibit a high absolute photoluminescence (PL) quantum yield (QY) of 67% and wonderful dispersibility in polar solvents. Then, solution blow spinning of CDs and polymer matrixes of alcohol soluble polyurethane (APU) and polyacrylonitrile (PAN) led to large-area fluorescent CDs-embedded nanofiber films, APU/CDs (size: 120 cm × 18 cm) and PAN/CDs (size: 120 cm × 22 cm), respectively. The resultant large-area APU/CDs and PAN/CDs nanofiber films have dramatically enhanced mechanical properties, to show integrated improvement of tensile strength and elongation.
Semiconductor-noble metal composite has become a research focus due to its superior performance compared with its respectⅳe component. Although various methods have been developed to synthesize semiconductor-noble metal heterostructures, most of them are relatⅳely complex multistep and use toxic reactants of high cost and risk. In this work, a series of Cu2O/Ag heterojunctions were quickly prepared in one step via simple microwave-assisted green route. XRD, SEM, TEM, EDS, XPS, etc. were used to characterize obtained products, and the results indicate a Cu2O/Ag metal-semiconductor heterojunction in micro-nano size was fabricated successfully. In addition, antibacterial behavior of Cu2O/Ag heterojunctions against E. coli and S. aureus were investigated. Owing to the synergistic effect of Cu2O and Ag, the heterojunction exhibits much better antibacterial performance than the pristine Cu2O does. This work provides new insights into the green design and fabrication of surface-modified Cu2O hybrid multifunctional materials for antibacterial applications.
Herein, the nanoscaled ATP-responsive upconversion metal-organic frameworks (UCMOFs) are aqueous-phase synthesized for co-delivery of therapeutic protein cytochrome c (Cyt c) and chemodrugs doxorubicin (DOX), achieving targeted combinational therapy of human cervical cancer. The UCMOFs are rationally fabricated by growing ZIF-90 on mesoporous silica-coated upconversion nanoparticles (UCNPs), in which the ZIF-90 layer attenuates the upconversion luminescence (UCL) and the rigid frameworks increase the stability of encapsulated proteins. Once the UCMOF@DOX/Cyt c are internalized into HeLa cells via specific recognition of sgc8 aptamers, the intracellular ATP triggers the dissolution of ZIF-90 into Zn2+, which facilitates not only the release of Cyt c and DOX but also the restoration of UCL for real-time monitoring of drug release. It has been demonstrated that the therapeutic efficacy is greatly improved by the combination of caspase-mediated apoptosis activated by Cyt c (protein therapeutics), DNA fragmentation induced by DOX (chemotherapy), and Zn2+-promoted generation of reactive oxygen species (ROS) (oxidative stress). Overall, our proposed multifunctional UCMOFs provide an effective platform for targeted combinational cancer therapy and in situ imaging, which hold great promise in biomedical and clinical applications.
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