Latest ArticlesQuantum dots (QDs), a type of nanoscale semiconductor material with unique optical and electrical properties like adjustable emission and high photoluminescence quantum yields, are suitable for applications in optoelectronics. However, QDs are typically degraded under humid and high-temperature circumstances, greatly limiting their practical value. Coating the QD surface with an inorganic silica layer is a feasible method for improving stability and endurance in a variety of applications. This paper comprehensively reviews silica coating methodologies on QD surfaces and explores their applications in optoelectronic domains. Firstly, the paper provides mainstream silica coating approaches, which can be divided into two categories: in-situ hydrolysis of silylating reagents on QD surfaces and template techniques for encapsulation QDs. Subsequently, the recent applications of the silica-coated QDs on optoelectronic fields including light-emitting diodes, solar cells, photodetectors were discussed. Finally, it reviews recent advances in silica-coated QD technology and prospects for future applications.
Supramolecular luminescent materials (SLMs) exhibit exceptional luminescence properties and the ability to be intelligently regulated through diverse assembly approaches, making them highly attractive in the field of luminescent materials. In recent years, the novel macrocyclic arenes characterized by unique electron-rich structures, ease of derivatization, tunable conformations and even inherent luminescence properties afford much opportunities to create such dynamic smart luminescent materials. The incorporation of macrocyclic arenes into SLMs leads to simple preparation process, diverse photophysical phenomena and sophisticated regulatory mechanisms, which is also currently one of the most frontier and hot topics in macrocyclic and supramolecular chemistry and even luminescent materials. In this review, the research advances in construction and applications of SLMs based on macrocyclic arenes in the last several years will be presented from the different assembly strategies, including host-guest complexes, supramolecular polymers, nanoparticles, and other assemblies. Moreover, some insights into future directions for this research area will also be offered.
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.
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.
Bacterial infection, insufficient angiogenesis, and oxidative damage are generally regarded as key issues that impede wound healing, making it necessary to prepare new biomaterials to simultaneously address these problems. In this work, monodispersed CeO2@CuS nanocomposites (NCs) were successfully prepared with tannin (TA) as the reductant and linker. Due to abundant oxygen vacancies in CeO2 and the polyphenolic structure of TA, the TA-CeO2@CuS NCs exhibited a remarkable antioxidant ability to scavenge excessive reactive oxygen species (ROS), which would likely induce serious inflammation. In addition, the TA-CeO2@CuS NCs demonstrated excellent antibacterial capability with near-infrared ray (NIR) irradiation, and the released copper ions could promote the regeneration of blood vessels. These synergistic effects indicated that the synthesized TA-CeO2@CuS NCs could serve as a promising biomaterial for multimodal wound therapy.
The efficacy of photodynamic therapy (PDT) for breast tumors is hindered by challenges such as inadequate tumor targeting, limited treatment depth, and strong oxygen dependence. Herein, a promising photosensitizer VP-B was developed to simultaneously address all the aforementioned issues for the treatment of hypoxic deep-seated breast tumors. The biotinylated photosensitizer VP-B not only exhibited precise targeting towards breast tumor tissue, but also efficiently triggered the generation of abundant 1O2 and O2−• under 690 nm red light irradiation. Indeed, the red light penetration ability enabled VP-B to achieve successful application in a mouse orthotopic breast tumor model. After intravenous administration, VP-B can selectively target tumor tissues and significantly inhibit the growth of hypoxic deep-seated tumors. Therefore, this new type Ⅰ & Ⅱ photosensitizer could boost fluorescence-guided photodynamic therapy of other hypoxic solid tumors.
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.
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.
Breath analysis can be used to diagnose diseases non-invasively. Accurate measurement of volatolomics is critical for breath analysis to be a gold standard. Tedlar bags (TB) are often used to collect breath samples, but they emit contaminants that affect accuracy. This issue was overlooked in previous studies. We found contamination issues with TB (e.g., siloxanes and aromatic impurities) that affect the identification of volatile organic compounds (VOCs) due to impurities. Then, home-designed equipment (HD) made with poly-tetrafluoride (PTFE) and quartz glass for breath collection was developed and employed in clinical trials. 15 healthy individuals and 32 non-small cell lung cancer (NSCLC) patients at IA stage participated in this study. 610 VOCs can be collected through TB, which is less than HD (1109 VOCs), demonstrating that the inner wall of the TB easily adsorbs VOCs, leading to decreased detection concentrations. Otherwise, utilizing orthogonal partial least squares discriminant analysis (OPLS-DA), we identified chemical markers with significant discriminatory power (VIP > 1.5, P < 0.05). The HD method identified 12 target VOCs, surpassing the 3 target VOCs discerned by the TB method. A model combined with a machine learning algorithm for distinguishing early-stage lung cancer patients was established based on biomarkers, which were selected based on OPLS-DA. The results showed strong predictive capabilities for the HD-based model. It indicated that 12 biomarkers derived from the HD model were more effective in distinguishing NSCLC patients, with an AUC value of 0.92, compared to the AUC value of 0.5 from 3 markers obtained from the TB model. The sensitivity and specificity in the confusion matrix reached 100% and 80% for the HD test, but TB test reached only 40% and 60%. This work demonstrated that optimizing and standardizing VOCs collection methodology from breath of lung cancer patients is essential to identify actual volatiles, which could promote disease volatolomics worldwide.
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.