Latest ArticlesAchieving high energy densities for all-solid-state lithium batteries is restricted by the poor high voltage stability of solid electrolytes. Herein, F-doping strategy is successfully employed on Li3InCl6 to obtain enhanced voltage stability and electrode compatability towards bare LiNi0.7Mn0.2Co0.1O2 at high voltages. The optimized Li3InCl5.5F0.5 electrolyte exhibits a decreased conductivity of 1.00 mS/cm, a wider voltage window, and improved electrochemical performance in solid-state batteries when cycled at upper cut-off voltages of 4.5 and 4.8 V (vs. Li+/Li0). The generation of more stable LiInF4 phase in the cathode mixture of Li3InCl5.5F0.5-based battery ensures superior electrochemical performances compared to the Li3InCl6-based battery. The former battery exhibits a higher discharge capacity of 218.9 mAh/g and coulombic efficiency of 86.7% for the first cycle, and retains 80.0% of its original value after 100 cycles when cycled in the range of 3.0–4.5 V (vs. Li+/Li0). In contrast, the Li3InCl6-based battery exhibits lower capacities and faster degradation under the same conditions due to the formation of InCl3 phase with poor electrochemical stability. This work facilitates the advancement of high energy density solid-state battery technologies by utilizing high-voltage cathodes.
Asperfilasin A (1), featuring a unique 5/5 cyclopenta[c]pyrrol-one bicyclic core, represents a newly discovered skeletal cytochalasan isolated from Aspergillus flavipes. The enantioselective total synthesis was efficiently accomplished from the key intermediate (S)-6 with three contiguous stereocenters in 5 steps and the synthetic 1 induced G2/M-phase cell cycle arrest of HT29 cells and apoptosis of HL60 and NB4 cells by activation of caspase-3 and degradation of PARP. (S)-6, bearing three contiguous chiral centers, was efficiently constructed by a novel Nazarov cyclization reaction containing basic nitrogen, which was less developed, primarily due to the incompatibility of basic nitrogen under acidic reaction conditions. This reaction allows a wide range of pentadienone substrates containing basic nitrogen to undergo Nazarov cyclization in a single regioselective and diastereoselective manner and is capable of generating three stereocenters simultaneously. Furthermore, the mechanism of the Nazarov cyclization and the origin of the regio- and diastereoselectivity were elucidated by DFT calculations and deuteration experiments, providing valuable insights into the reaction and serving as a guide for future applications involving substrates containing basic nitrogen.
Molecularly imprinted polymers (MIPs) are a kind of synthetic receptors possessing wide application prospects in proteins recognition. However, there are still great challenges in proteins imprinting due to their large size and easy conformation change. In this study, we explored epitope-oriented MIP based on host-guest interaction (hg-MIP) and constructed a novel hg-MIP-SERS (surface-enhanced Raman scatting) approach for efficiently recognizing the terminal epitopes of neuron-specific enolase (NSE), a well-known disease biomarker for small cell lung cancer, neuroblstom, and Alzheimer's disease. The C- and N-terminal epitopes of NSE were modified with 4-(phenylazo) benzoic acid, then they were used as the templates and immobilized on β-cyclodextrin-functionalized substrates. The imprinted layer was formed by polymerization of various functional monomers. Combined with SERS detection, an antibody-free sandwich assay based on hg-MIP was successfully used to detect the concentration of NSE in human serums, with the advantages of simple operation, small sample volume (5 µL), wide linear range (1–104 ng/mL) and a limit of detection as low as 0.01 ng/mL. The developed epitope-oriented hg-MIP-SERS approach can also be extended to other proteins, expanding the imprinting method of proteins, and has a broad development space in the field of protein separation and detection.
Receptor tyrosine kinases (RTKs) are biological enzymes expressed on cell membranes that can influence cellular signaling, and their overexpression in tumor cells makes them a key route to assess relevant tumor processes. The development of a delivery system that targets and accumulates in RTKs overexpressing-cells at the on-target site is significant for the monitoring of tumor progression and clinical applications through longer tumor site signaling response under low injection frequency. Here, a host-guest nanoscale fluorescent probe SNI@ZIF-8 based on zeolitic imidazolate framework-8 (ZIF-8) and a fluorescent probe SNI constructed from receptor tyrosine kinase inhibitor was proposed and prepared for targeting RTKs and enabling prolonged fluorescence imaging in vivo. The folded conformation of the probe SNI resulted in low background fluorescence, and the unfolding of the SNI conformation upon insertion of the RTKs active pocket showed significant fluorescence enhancement thus enabling real-time detection of RTKs. The host-guest system SNI@ZIF-8 could release guest molecules due to the presence of the enzyme, emphasizing the reporting of stable fluorescent signals over time under low injection frequency. SNI@ZIF-8 could provide a signal response on the cell membrane of RTKs overexpressing cells without interference from other substances, and provided a longer fluorescent signal than SNI at equivalent number of injections in tumor-bearing mice. The host-guest system SNI@ZIF-8, with its obvious tumor site enrichment ability and clear fluorescence imaging ability, could be successfully applied to the detection of RTKs on cell membranes in biological systems, providing a new strategy for determining the process of tumor development in clinical applications.
Electrocatalytic water splitting for hydrogen production is a key approach to tackling the current energy crisis. Among the catalysts, the traditional Pd@C catalysts are remarkable for their efficiency in hydrogen evolution. However, the high cost and scarcity of Pd catalysts, as well as the instability caused by the corrosiveness of carbon-based substrates, hinder their large-scale application. To overcome this challenge, an effective strategy is to construct highly dispersed Pd single atoms to improve palladium utilization and choose more stable materials as supports. In this study, TiO2−x carriers with abundant oxygen vacancies were prepared and loaded with Pd by photoreduction deposition. Adjusting the palladium content resulted in three forms of Pd-loaded TiO2−x: nanoparticles (Pd@TiO2−x(6%, 10%)), nanoclusters (Pd@TiO2−x(3%)) and single atoms (Pd@TiO2−x(1.5%)). The oxygen vacancies improved the stability of the titanium dioxide materials by providing more active hydrogen adsorption sites and increasing the affinity of Pd for active hydrogen. Single atom loading increased the frequency of oxygen holes in the support and the high activity of monatomic Pd promoted the adsorption of active hydrogen and facilitated the formation of active hydrogen intermediates. The synergistic effect of single atoms and oxygen vacancies improved the stability and catalytic activity of the composite material. Pd@TiO2−x(1.5%) showed outstanding performance in hydrogen evolution in an acidic medium with an overpotential of only 24 mV at a current density of 10 mA/cm2 and a low Tafel rise of 41.9 mV/dec. This study provides an effective strategy for the development of high-performance hydrogen evolution (HER) catalysts.
Although diverse signal-amplified methods have been committed to improve the sensitivity of surface plasmon resonance (SPR) biosensing, introducing convenient and robust signal amplification strategy into SPR biosensing remains challenging. Here, a novel nanozyme-triggered polymerization amplification strategy was proposed for constructing highly sensitive surface plasmon resonance (SPR) immunosensor. In detail, Au@Pd core-shell nanooctahedra nanozyme with superior peroxidase (POD)-like activity was synthesized and utilized as a label probe. Simultaneously, Au@Pd core-shell nanooctahedra nanozyme can catalyze the decomposition of H2O2 to form hydroxyl radicals (•OH) that triggers the polymerization of aniline to form polyaniline attaching on the surface of sensor chip, significantly amplifying SPR responses. The sensitivity of SPR immunosensor was enhanced by nanozyme-triggered polymerization amplification strategy. Using human immunoglobulin G (HIgG) as a model, the constructed SPR immunosensor obtains a wide linear range of 0.005–1.0 µg/mL with low detection limit of 0.106 ng/mL. This research provides new sights on establishing sensitive SPR immunosensor and may evokes more inspiration for developing signal amplification methods based on nanozyme in biosensing.
Currently, it is still a challenge to develop an organic photosensitizer (PS) with outstanding near-infrared absorption, low O2 dependence, precise tumor targeting and rapid clearance through the kidney to improve the overall outcome of phototherapy. In this study, we have designed an organic PS (NcPB) with an excellent near-infrared light absorption through a refined molecular strategy. Meanwhile, NcPB was assembled into nanoparticles with different sizes (NanoNcPB-1 and NanoNcPB-0) by a supramolecular modulation strategy. As the results, the nanoparticle with an ultra-small size (NanoNcPB-1) generated a large number of superoxide anion (O2•−) in a low-O2-dependent manner and release plenty of heat. Furthermore, the results of in vivo experiments demonstrated that NanoNcPB-1 actively accumulated in tumor tissues and showed a 92% tumor inhibition after photodynamic and photothermal combination therapy. More importantly, NanoNcPB-1 could be rapidly cleared from the body of mice via the renal pathway, which alleviates potential side effects of prolonged retention of PS in the circulation.
As PEGylated liposomes have witnessed remarkable advancements in drug delivery, their immunogenicity has emerged as a notable challenge. In this study, we discovered that a simple pre-injection of folic acid (FA) effectively mitigated the immunogenicity of PEGylated liposomes and enhanced their in vivo performance by tolerating splenic marginal zone B cells. FA specifically inhibited the internalization of PEGylated liposomes by splenic marginal zone B cells, thereby reducing splenic lymphocyte proliferation and specific IgM secretion. This modulation alleviated IgM-mediated accelerated blood clearance and adverse accumulation of the PEGylated liposomes in the skin. These findings provide new insights into the immunomodulatory effects of FA and promising avenues to enhance the efficacy and safety of PEGylated liposomal nanomedicines.
H2O2 is an environmentally friendly oxidizing agent with minimal secondary pollution; however, its application has always been constrained by factors such as storage and transportation. In this study, we propose an innovative method for storing and releasing H2O2 using hydrogels. Commercial hydrogels (sodium polyacrylate) can undergo swelling and absorb H2O2 in aqueous solutions, and the swollen hydrogel can continuously release H2O2 under osmotic pressure. And the characteristics of osmotic pressure drive ensure the recyclability of hydrogel for H2O2 storage. Experimental results demonstrate that H2O2 can stably exist within the hydrogel for an extended period, and this strategy helps to avoid explosion the risk and potential environmental hazards during the transportation of H2O2. Finally, experiments confirm that the hydrogel controlled sustained release of H2O2 is effective in both Fenton reactions and the process of bacterial inactivation. This work introduces new ideas for the storage of H2O2, and the sustained release of H2O2 may have significant implications in the fields of healthcare, environmental science, catalysis, and beyond.
Graphene quantum dots (GQDs) are a class of promising carbon-based nanomaterials that have attracted considerable interest from researchers due to their excellent physical, chemical, and biological properties. However, the high cost, toxicity, and laborious preparation process of GQDs also limit their widespread use. To address this issue, the actual research directions consist in replacing traditional non-renewable feedstocks via screening cheap, easily available, and renewable biomass materials based on the concept of resource conservation and environmental friendliness. Herein, the state-of-the-art technologies in the green preparation of GQDs using biomass as carbon source are reported. Initially, the green synthesis strategies as well as the structural, optical, and biosafety properties of GQDs are discussed in detail. Subsequently, the most representative applications of GQDs in energy and environmental remediation fields are summarized. Finally, the current challenges and future potential of the GQDs are presented.