Phase and Defect Engineering of MoSe2 Nanosheets for Enhanced NIR-II Photothermal Immunotherapy.

Inducing immunogenic cell death (ICD) during photothermal therapy (PTT) has the potential to effectively trigger photothermal immunotherapy (PTI). However, ICD induced by PTT alone is often limited by inefficient PTT, low immunogenicity of tumor cells, and a dysregulated redox microenvironment. Herein, we develop MoSe2 nanosheets with high-percentage metallic 1T phase and rich exposed active Mo centers through phase and defect engineering of MoSe2 as an effective nanoagent for PTI. The metallic 1T phase in MoSe2 nanosheets endows them with strong PTT performance, and the abundant exposed active Mo centers endow them with high activity for glutathione (GSH) depletion. The MoSe2-mediated high-performance PTT synergizing with efficient GSH depletion facilitates the release of tumor-associated antigens to induce robust ICD, thus significantly enhancing checkpoint blockade immunotherapy and activating systemic immune response in mouse models of colorectal cancer and triple-negative metastatic breast cancer.

Facile Synthesis of High Molecular Weight Poly(ethylene glycol)-b-poly(amino acid)s by Relay Polymerization.

Poly(amino acid)s (PAAs) are one kind of favorable biopolymer that can be used as a drug or gene carrier. However, conventional ring-opening polymerization of PAAs is slow and needs a strict anhydrous environment with an anhydrous reagent as well as the product without enough high molecular weight (Mn), which limits the expanding of PAAs' application. Herein, we took BLG-NCA as the monomer to quickly synthesize one kind of high Mn amphiphilic copolymer, poly(ethylene glycol)-b-poly(γ-benzyl-l-glutamic acid) (PEG-PBLG), by relay polymerization with a simple one-pot method within 3 h in mild conditions (open air, moisture insensitive). In the polymerization process, ring-opening polymerization-induced self-assembly in sodium bicarbonate aqueous solution first occurred to obtain low Mn PEG-PBLG seeds without purification. Then γ-benzyl-l-glutamate N-carboxyanhydride (BLG-NCA) dichloromethane solution was added into PEG-PBLG seeds directly and stirred vigorously to form am emulsion; during this process, the amphiphilic PEG-PBLG seeds will anchor on the interface of DCM and water to ensure the concentration of α-helix rigid PBLG in DCM to maintain the following relay polymerization. Then, high Mn PEG-PBLG was obtained in mild conditions in one pot. We found that the α-helix rigid structure was essential for relay polymerization by studying the synthetic speed of amphiphilic copolymer with different secondary structures. MOE simulation results showed that PBLG and BLG-NCA tended to form a double hydrogen bond, which was beneficial to relay polymerization because of higher local concentrations that can produce more double hydrogen bonds. Our strategy can quickly obtain high Mn PEG-PBLG (224.9 KDa) within 3 h from PEG-NH2 and BLG-NCA in one pot and did not need an extra initiator. After deprotection, the poly(ethylene glycol)-b-poly(l-glutamate acid) (PEG-PGA) with high Mn as a second product can be used as an excellent antitumor drug carrier. The high Mn PEG-PGA can achieve an encapsulation rate of 86.7% and a drug loading rate of 47.3%, which is twice that of the low Mn PEG-PGA. As a result, the synthesis of PEG-PBLG by relay polymerization simplified the process of PEG-PAA polymerization and increased the Mn. In addition, this method opened a way to obtain other kinds of high Mn PEG-PBLG values in the future.

Use of ultrasound imaging Omics in predicting molecular typing and assessing the risk of postoperative recurrence in breast cancer.

BACKGROUND: The aim of this study is to assess the efficacy of a multiparametric ultrasound imaging omics model in predicting the risk of postoperative recurrence and molecular typing of breast cancer. METHODS: A retrospective analysis was conducted on 534 female patients diagnosed with breast cancer through preoperative ultrasonography and pathology, from January 2018 to June 2023 at the Affiliated Cancer Hospital of Xinjiang Medical University. Univariate analysis and multifactorial logistic regression modeling were used to identify independent risk factors associated with clinical characteristics. The PyRadiomics package was used to delineate the region of interest in selected ultrasound images and extract radiomic features. Subsequently, radiomic scores were established through Least Absolute Shrinkage and Selection Operator (LASSO) regression and Support Vector Machine (SVM) methods. The predictive performance of the model was assessed using the receiver operating characteristic (ROC) curve, and the area under the curve (AUC) was calculated. Evaluation of diagnostic efficacy and clinical practicability was conducted through calibration curves and decision curves. RESULTS: In the training set, the AUC values for the postoperative recurrence risk prediction model were 0.9489, and for the validation set, they were 0.8491. Regarding the molecular typing prediction model, the AUC values in the training set and validation set were 0.93 and 0.92 for the HER-2 overexpression phenotype, 0.94 and 0.74 for the TNBC phenotype, 1.00 and 0.97 for the luminal A phenotype, and 1.00 and 0.89 for the luminal B phenotype, respectively. Based on a comprehensive analysis of calibration and decision curves, it was established that the model exhibits strong predictive performance and clinical practicability. CONCLUSION: The use of multiparametric ultrasound imaging omics proves to be of significant value in predicting both the risk of postoperative recurrence and molecular typing in breast cancer. This non-invasive approach offers crucial guidance for the diagnosis and treatment of the condition.

Copper-Coordinated Covalent Organic Framework Produced a Robust Fenton-Like Effect Inducing Immunogenic Cell Death of Tumors.

Increasing infiltration of CD8+ T cells can enhance the response rate to immune checkpoint blockade (ICB) therapies. In contrast, immunogenic cell death (ICD) induced by intracellular reactive oxygen species (ROS) is an effective strategy to increase CD8+ T cell infiltration. Cuproptosis is newly defined and reported by Tsvetkov et al. A Cu-coordinated covalent organic framework (COF) in which two valence states of copper ions are simultaneously loaded is prepared. On the one hand, Cu2+ undergoes a valence shift generating Cu+ which acts as an effective Fenton-like reagent to catalyze the production of · OH and 1 O2 from cellular overexpressed H2 O2 , causing DNA damage and lipid peroxidation (LPO), which directly produce cytotoxicity. On the other hand, residual Cu2+ can effectively deplete endogenous cellular glutathione (GSH), converting it into glutathione disulfide (GSSG), further increasing intracellular oxidative stress and reducing the scavenging of ROS, thus further enhancing the Fenton-like effect and bringing toxic effects on tumor cells. The synergy of these two functions achieves ICD, helping for transforming "cold tumor" into "hot tumor" and efficient anti-tumor effects eventually. This work provides new insights into coordinated COF and inspire the development of more versatile COF for biomedical applications.

Relationship Between Prognostic Nutritional Index and New-Onset Atrial Fibrillation in Patients with Acute ST-Elevation Myocardial Infarction Following Percutaneous Coronary Intervention.

Multiple reports relate new-onset atrial fibrillation (NOAF) to poor clinical outcomes in patients with ST-elevation myocardial infarction (STEMI) who received percutaneous coronary intervention (PCI). The prognostic nutritional index (PNI) is a reliable indicator of immunonutritional-inflammatory status, and it is linked to clinical outcomes in cardiovascular disease patients. This research aims to explore the relationship between NOAF and PNI.Overall, 600 STEMI patients treated with PCI were recruited for this retrospective analysis. The patients were categorized into the NOAF group or sinus rhythm (SR) group. Logistic regression and receiver operating characteristic (ROC) curve analyses were conducted to assess PNI estimation. Lastly, the Kaplan-Meier curve was used to compare all-cause mortality between both groups.The combined NOAF incidence in PCI-treated STEMI patients was 7.7%. PNI was independently correlated with NOAF using multivariate regression analyses (odds ratio [OR], 0.824; 95% confidence interval [CI], 0.750-0.906; P < 0.001). In ROC curve analyses, the best PNI threshold value for predicting NOAF was 40.1, with sensitivity, and specificity of 76.09% and 71.30%, respectively area under the curve, 0.787; 95% CI, 0.752-0.819; P < 0.001). After a median of 41-month follow-up, the Kaplan-Meier curve revealed that the NOAF patients displayed an elevated all-cause death incidence compared with SR patients, with a log-rank of P = 0.005.This study demonstrated that PNI is an independent predictor of NOAF in STEMI patients during hospitalization after PCI, which is strongly correlated with a poor outcome upon discharge.

Biomimetic 3D Recognition with 2D Flexible Nanoarchitectures for Ultrasensitive and Visual Extracellular Vesicle Detection.

Despite increasing recognition of extracellular vesicles being important circulating biomarkers in disease diagnosis and prognosis, current strategies for extracellular vesicle detection remain limited due to the compromised sample purification and extensive labeling procedures in complex body fluids. Here, we developed a 2D magnetic platform that greatly improves capture efficiency and readily realizes visible signal conversion for extracellular vesicle detection. The technology, termed high-affinity recognition and visual extracellular vesicle testing (HARVEST), leverages 2D flexible Fe3O4-MoS2 nanostructures to recognize extracellular vesicles through multidentate affinity binding and feasible magnetic separation, thus enhancing the extracellular vesicle capture performance with both yield and separation time, affording high sensitivity with the detection limit of 20 extracellular vesicle particles/µL. Through integration with lipid labeling chemistry and the fluorescence visualization system, the platform enables rapid and visible detection. The number of extracellular vesicles can be feasibly determined by smart mobile phones, readily adapted for point-of-care diagnosis. When clinically evaluated, the strategy accurately differentiates melanoma samples from the normal cohort with an AUC of 0.98, demonstrating the efficient extracellular vesicle detection strategy with 2D flexible platforms for cancer diagnosis.

Metallic 1T Phase Enabling MoS2 Nanodots as an Efficient Agent for Photoacoustic Imaging Guided Photothermal Therapy in the Near-Infrared-II Window.

Transition metal dichalcogenide (TMD) nanomaterials, specially MoS2 , are proven to be appealing nanoagents for photothermal cancer therapies. However, the impact of the crystal phase of TMDs on their performance in photoacoustic imaging (PAI) and photothermal therapy (PTT) remains unclear. Herein, the preparation of ultrasmall single-layer MoS2 nanodots with different phases (1T and 2H phase) is reported to explore their phase-dependent performances as nanoagents for PAI guided PTT in the second near-infrared (NIR-II) window. Significantly, the 1T-MoS2 nanodots give a much higher extinction coefficient (25.6 L g-1  cm-1 ) at 1064 nm and subsequent photothermal power conversion efficiency (PCE: 43.3%) than that of the 2H-MoS2 nanodots (extinction coefficient: 5.3 L g-1  cm-1 , PCE: 21.3%). Moreover, the 1T-MoS2 nanodots also give strong PAI signals as compared to negligible signals of 2H-MoS2 nanodots in the NIR-II window. After modification with polyvinylpyrrolidone, the 1T-MoS2 nanodots can be used as a highly efficient agent for PAI guided PTT to effectively ablate cancer cells in vitro and tumors in vivo under 1064 nm laser irradiation. This work proves that the crystal phase plays a key role in determining the performance of nanoagents based on TMD nanomaterials for PAI guided PTT.

A peptide delivery system sneaks CRISPR into cells.

The CRISPR-Cas9 system has developed into a powerful platform for genome editing in various types of cells and tissues with single-nucleotide precision, but limited delivery options hamper its application in real-world settings. A new study by Shen et al. describes the use of an amphipathic peptide to deliver Cas9/sgRNA ribonucleoprotein complexes, leading to the disruption of GFP genes in cells and mice. Disruption of the Nrip1 gene in isolated pre-adipocytes led to a "browning" phenotype, pointing to new options in the fight against diabetes and obesity.

Facile one-step targeted immobilization of an enzyme based on silane emulsion self-assembled molecularly imprinted polymers for visual sensors.

Immobilized enzymes play significant roles in many practical applications. However, the enzymes need to be purified before immobilization by conventional immobilizing methods, and the purification process is expensive, laborious, complicated and results in a decrease of the enzymatic activity. So, we present a novel method by a facile one-step targeted immobilization of an enzyme without a purification process from complex samples. For this purpose, a novel molecularly imprinted polymer was prepared via a silane emulsion self-assembly method using boric acid-modified Fe3O4 nanoparticles as magnetic nuclei, horseradish peroxidase as a template, 3-aminopropyltriethoxysilane as a functional monomer and tetraethyl orthosilicate as a crosslinking agent. The molecularly imprinted polymers were characterized using a scanning electron microscope, X-ray photoelectron spectroscope, vibrating sample magnetometer and X-ray diffractometer. The as-prepared and characterized materials were employed to immobilize horseradish peroxidase from a crude extract of horseradish. Moreover, the immobilized horseradish peroxidase was employed to develop visual sensors for the detection of glucose and sarcosine. This study demonstrated that the molecularly imprinted polymers prepared via the silane emulsion self-assembly method can facilely immobilize horseradish peroxidase from a crude extract of horseradish without any purification process. The developed visual method based on the immobilized horseradish peroxidase shows great potential applications for the visual detection of glucose and sarcosine.

Molecularly imprinted polymer solid-phase microextraction coupled with ultra high performance liquid chromatography and tandem mass spectrometry for rapid analysis of pyrrolizidine alkaloids in herbal medicine.

Pyrrolizidine alkaloids are the most widely distributed natural toxins, and pyrrolizidine alkaloid-containing herbal medicines are probably the most common poisonous plants affecting humans. We reported pyrrolizidine alkaloid-molecularly imprinted polymer solid-phase microextraction for the selective adsorption of toxic pyrrolizidine alkaloids from herbal medicine. A sulfonic compound, sodium allylsulfonate, was chosen as the functional monomer to interact with pyrrolizidine alkaloids through strong ionic interaction. To avoid template leakage and for the aim of cost saving, a relatively cheap dummy template was used for the fabrication of molecularly imprinted polymer-solid-phase microextraction fibers. The obtained fibers showed selective adsorption ability for four pyrrolizidine alkaloids, including europine, echimidine, lasiocarpine, and heliotrine. The extraction parameters, such as extraction time, extraction temperature, shaking speed, elution solvent and elution time, were optimized. Then ultra high performance liquid chromatography with mass spectrometry coupled with molecularly imprinted polymer-solid-phase microextraction method was developed for the fast and efficient analysis of four pyrrolizidine alkaloids from the model herbal plant Farfarae Flos. The established method was validated and exhibited satisfactory accuracy and precision. The present method provides an innovative and fast analytical strategy for the determination of trace toxic pyrrolizidine alkaloids in complicated samples.

Single-Molecule Analysis of MicroRNA and Logic Operations Using a Smart Plasmonic Nanobiosensor.

Analysis of biomolecules at the single-molecule level is a great challenge in molecular diagnostics, gene profiling, and environmental monitoring. In this work, we design a smart plasmonic nanobiosensor based on individual Au@Ag core-shell nanocube (Au@Ag NC) modified with tetrahedron-structured DNA (tsDNA) for detecting microRNA 21 (miR-21) at the single-molecule level. An average localized surface plasmon resonance (LSPR) scattering spectral wavelength shift of approximately 0.4 nm can be obtained for a single miR-21 hybridization event on the nanobiosensor. In addition, the sensing mechanism of the individual Au@Ag NC is further verified by the three-dimensional finite-difference time-domain (3D-FDTD) simulations. Notably, this system not only allows the real-time detection of miR-21 with an aM level sensitivity over a large dynamic range from 1 aM to 1 nM, but also enables DNA-based logic operations as well as biomemory by exploiting miR-21, KpnI, and StuI-responsive assays. Our study opens a unique method for single-molecule detection of biomolecules and thus holds great promise in a variety of biological and biomedical applications.

Preparation of 1T'-Phase ReS2 xSe2(1- x) ( x = 0-1) Nanodots for Highly Efficient Electrocatalytic Hydrogen Evolution Reaction.

As a source of clean energy, a reliable hydrogen evolution reaction (HER) requires robust and highly efficient catalysts. Here, by combining chemical vapor transport and Li-intercalation, we have prepared a series of 1T'-phase ReS2 xSe2(1- x) ( x = 0-1) nanodots to achieve high-performance HER in acid medium. Among them, the 1T'-phase ReSSe nanodot exhibits the highest hydrogen evolution activity, with a Tafel slope of 50.1 mV dec-1 and a low overpotential of 84 mV at current density of 10 mA cm-2. The excellent hydrogen evolution activity is attributed to the optimal hydrogen absorption energy of the active site induced by the asymmetric S vacancy in the highly asymmetric 1T' crystal structure.

Reduction of graphene oxide quantum dots to enhance the yield of reactive oxygen species for photodynamic therapy.

The production of reactive oxygen species (ROS) from graphene oxide quantum dots (GOQDs) and chemically reduced GOQDs (rGOQDs) was studied. This shows that GOQDs and rGOQDs produce ROS including singlet oxygen (1O2), hydrogen peroxide (H2O2) and superoxide anion (O2˙-). Interestingly, the rGOQDs exhibit a higher yield of ROS under white light in comparison with GOQDs, indicating the enhanced photodynamic effect through chemical reduction of GOQDs. Studies on the relation between their structures and the yield of ROS demonstrate that the reduction of GOQDs with hydrazine hydrate decreases the band gap and valence band of GOQDs and results in more electron-hole pairs, which leads to an improvement in the yield of ROS from rGOQDs. This research explores the specific species of ROS generated from GOQDs, and provides an efficient avenue to improve the yield of ROS through surface modification of GOQDs.

Facile preparation of polydopamine-coated imprinted polymers on the surface of SiO2 for estrone capture in milk samples.

Estrone molecularly imprinted polymers were synthesized through the self-polymerization of dopamine on the surface of silica gels, which had the characteristics of mild polymerization conditions, simple reaction procedure and good specific recognition ability for estrone. The estrone molecularly imprinted polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and nitrogen adsorption-desorption tests. The characterization confirmed that the imprinted polymers were successfully grafted on the surface of silica gels. Through investigating the adsorption performance, the prepared estrone molecularly imprinted polymers exhibited high adsorption capacity, fast mass transfer, as well as excellent selectivity toward estrone. The estrone molecularly imprinted polymers as the solid-phase extraction adsorbent coupled with high-performance liquid chromatography was developed to determine estrone from the milk samples. The developed estrone molecularly imprinted polymer solid-phase extraction with high-performance liquid chromatography method exhibited satisfactory specificity, precision, accuracy and good linearity relationship in the range of 0.2-20 µg/mL. The developed method is simple, fast, effective and high specificity method and it provides a new method to detect the residues of estrone in animal foods.

A Novel "Off-On" Fluorescent Probe Based on Carbon Nitride Nanoribbons for the Detection of Citrate Anion and Live Cell Imaging.

A novel fluorescent "off-on" probe based on carbon nitride (C3N4) nanoribbons was developed for citrate anion (C6H5O73-) detection. The fluorescence of C3N4 nanoribbons can be quenched by Cu2+ and then recovered by the addition of C6H5O73-, because the chelation between C6H5O73- and Cu2+ blocks the electron transfer between Cu2+ and C3N4 nanoribbons. The turn-on fluorescent sensor using this fluorescent "off-on" probe can detect C6H5O73- rapidly and selectively, showing a wide detection linear range (1~400 µM) and a low detection limit (0.78 µM) in aqueous solutions. Importantly, this C3N4 nanoribbon-based "off-on" probe exhibits good biocompatibility and can be used as fluorescent visualizer for exogenous C6H5O73- in HeLa cells.

Selective analysis of aristolochic acid I in herbal medicines by dummy molecularly imprinted solid-phase extraction and HPLC.

In this study, surface molecularly imprinted polymers were prepared as the selective sorbents for separation of aristolochic acid I in herbal medicine extracts by a facile approach. A less toxic dummy template, ofloxacin, was used to create specific molecule recognition sites for aristolochic acid I in the synthesized polymers. The polymers were characterized by Fourier-transfer infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, elemental analysis, and nitrogen adsorption-desorption test. The adsorption capacity was calculated using adsorption kinetics, selectivity, and recycling experiments. The obtained polymers exhibited high thermostability, fast equilibrium time, and excellent binding ability. Subsequently, the polymers applied as the solid-phase extraction absorbent was proposed and used for the enrichment and analysis of aristolochic acid I in herbal plants. The result showed that the aristolochic acid I was enriched up to 16 times after analysis by using high-performance liquid chromatography. The good linearity for aristolochic acid I was obtained in the range of 0.1-200 µg/mL (R2  = 0.9987). The recovery and precision values were obtained (64.94-77.73%, RSDs% ≤ 0.8%, n = 3) at three spiked concentration levels. This work provided a promising method for selective enrichment, extraction, and purification of aristolochic acid I from complex herbal plants.

Enrichment of total steroidal saponins from the extracts of Trillium tschonoskii Maxim by macroporous resin and the simultaneous determination of eight steroidal saponins in the final product by HPLC.

An effective and simple method was established for the separation and enrichment of steroidal saponins from Trillium tschonoskii Maxim. The adsorption and desorption properties of seven macroporous resins were investigated. Among the tested resins, AB-8 resin showed the best adsorption and desorption capacities. The adsorption of steroidal saponins on AB-8 at 25°C was quite consistent with both the Freundlich isotherm model and the pseudo-second-order kinetics model. By optimizing the dynamic adsorption and desorption parameters, the content of steroidal saponins increased from 5.20% in the crude extracts to 51.93% in the final product, with a recovery yield of 86.67%. Furthermore, by scale-up separation, the concentration and recovery of total steroidal saponins were 43.8 and 85.5%, respectively, which suggested that AB-8 resin had great industrial and pharmaceutical potential because of its high efficiency and cost-effectiveness. In addition, a high-performance liquid chromatography method for the simultaneous determination of eight steroidal saponins was established for the first time, which was employed to qualitatively and quantitatively analyze the final product. Based on the methodological validation results, the high-performance liquid chromatography method can be widely applied to the quality control of steroidal saponins from Trillium tschonoskii Maxim due to its excellent accuracy, stability, and repeatability.

Microdissection of the Ah01 chromosome in upland cotton and microcloning of resistance gene anologs from the single chromosome.

BACKGROUND: Chromosome microdissection is one of the most important techniques in molecular cytogenetic research. Cotton (Gossypium Linnaeus, 1753) is the main natural fiber crop in the world. The resistance gene analog (RGA) cloning after its single chromosome microdissection can greatly promote cotton genome research and breeding. RESULTS: Using the linker adaptor PCR (LA-PCR) with the primers of rice disease-resistance homologues, three nucleotide sequences PS016 (KU051681), PS054 (KU051682), and PS157 (KU051680) were obtained from the chromosome Ah01 of upland cotton (cv. TM-1). The Blast results showed that the three sequences are the nucleotide binding site-leucine rich repeat (NBS-LRR) type RGAs. Clustering results indicated that they are homologous to these published RGAs. Thus, the three RGAs can definitely be confirmed as NBS-LRR class of RGAs in upland cotton. CONCLUSIONS: Using single chromosome microdissection technique, DNA libraries containing cotton RGAs were obtained. This technique can promote cotton gene cloning, marker development and even the improvement of cotton genome research and breeding.

Evaluation of the chemical composition, antioxidant and anti-inflammatory activities of distillate and residue fractions of sweet basil essential oil.

In this study, the chemical composition and antioxidant and anti-inflammatory activities of sweet basil (Ocimum basilicum L. Lamiaceae family) were evaluated. Sweet basil is a food-related plant that is widely used in traditional Chinese medicine. Sweet basil crude oil was processed via molecular distillation and further characterized using gas chromatography-mass spectrometry (GC-MS) to screen for new compounds. The GC-MS analysis identified thirty-eight compounds. The major constituents of the residue fraction were estragole (17.06%), methyl eugenol (11.35%) and linoleic acid (11.40%), while the distillate fraction primarily contained methyl eugenol (16.96%), α-cadinol (16.24%) and α-bergamotene (11.92%). The antioxidant (DPPH and ABTS assays) and anti-inflammatory (in Raw264.7 cells) activities were evaluated. The residue fraction markedly scavenged the DPPH (IC50 = 1.092 ± 0.066 mg/mL) and ABTS (IC50 = 0.707 ± 0.042 mg/mL) radicals. Meanwhile, the distillate fraction distinctly suppressed the production of cytokines (TNF-α, IL-ß, IL-6) and their gene expression in LPS-induced Raw264.7 cells and suppressed NO and iNOS in an in vitro model when compared with the crude oil. In conclusion, the fractions obtained from sweet basil crude oil showed different antioxidant and anti-inflammatory properties, and they could be used as an effective source of natural antioxidant and anti-inflammatory agents after molecular distillation. Thus, the properties of essential oils in natural herbal medicines may be maximized to provide a valuable therapeutic strategy for treating various disorders caused by extreme oxidative stress.

Synthesis of WOn -WX2 (n=2.7, 2.9; X=S, Se) Heterostructures for Highly Efficient Green Quantum Dot Light-Emitting Diodes.

Preparation of two-dimensional (2D) heterostructures is important not only fundamentally, but also technologically for applications in electronics and optoelectronics. Herein, we report a facile colloidal method for the synthesis of WOn -WX2 (n=2.7, 2.9; X=S, Se) heterostructures by sulfurization or selenization of WOn nanomaterials. The WOn -WX2 heterostructures are composed of WO2.9 nanoparticles (NPs) or WO2.7 nanowires (NWs) grown together with single- or few-layer WX2 nanosheets (NSs). As a proof-of-concept application, the WOn -WX2 heterostructures are used as the anode interfacial buffer layer for green quantum dot light-emitting diodes (QLEDs). The QLED prepared with WO2.9 NP-WSe2 NS heterostructures achieves external quantum efficiency (EQE) of 8.53 %. To our knowledge, this is the highest efficiency in the reported green QLEDs using inorganic materials as the hole injection layer.