Latest ArticlesMetal nanoparticles (MNPs) possess size-dependent desirable electronic and optical properties while metal-organic frameworks (MOFs) have an edge over extremely large specific surface areas, homogeneous structure, high porosity and remarkable chemical stability. Their combination (MNPs/MOFs) is a novel nanomaterial with broad application prospect in sensing field. To improve performance in sensing applications, we have paid great attention to synergistic effects between the two compositions above. Because of the synergistic effects between MNPs and MOFs, sensors on the basis of MNPs/MOFs composites show significant sensing enhancement with respect to stability, selectivity and sensitivity. In this review, various applications for MNPs/MOFs composites in electrochemical sensing, fluorescent sensing, colorimetric sensing, surface-enhanced Raman scattering sensing and chemiluminescence/electrochemiluminescence sensing are focused and summarized. Besides, the synergistic interactions between MNPs and MOFs was investigated. Finally, based on theoretical information from the reports as well as experimental experience, this review offers the challenges and opportunities for future research on MNPs/MOFs composites.
Hypoxic tumor microenvironment is a major challenge for photodynamic therapy (PDT). To overcome this problem, PDT combined hypoxia-activated chemotherapy is a promising strategy for hypoxic cancer therapy. Herein, a multifunctional liposome (AQ4N-Ir1-sorafenib-liposome) is prepared by encapsulating a hypoxia-activated prodrug AQ4N, a photosensitizer iridium(Ⅲ) complex and hepatocellular carcinoma (HCC) targeting drug sorafenib, for synergistic therapy of HCC. Ir1-mediated PDT upon irradiation induces ROS generation and hypoxic environment, which leads to the disassembly of the liposome and activates the antitumor activity of AQ4N. Meantime, the co-delivered sorafenib could effectively target therapy of HCC. It is noted that ferroptosis mechanism is proved during the treatment. This work contributes to the design of hypoxia-responsive multifunctional liposome for combination of chemotherapy, targeting therapy and PDT. It is a promising strategy for hypoxic HCC therapy.
Controlling the particle size of catalyst to understand the active sites is the key to design efficient electrocatalysts toward hydrogen electrode reactions including hydrogen oxidation and evolution (HOR/HER). Herein, the hydrogen and hydroxyl adsorption on Ru/C could be effectively tuned for HOR/HER by simple controlling the particle sizes. It is found that the metallic Ru (Ru0) is the active site for HOR/HER, while oxidized Ru (Rux+) will hinder the adsorption and desorption of hydrogen on the catalyst. For the HOR, catalyst with small particles is more efficient, due to it is a three-phase interface reaction of gas on the surface of the catalyst. For the HER, the metallic state of Ru is crucial. The deconvolution of hydrogen peaks indicates that the catalytic sites with low hydrogen binding energy (HBE) shoulder the majority of the HOR activity. CO stripping curve further demonstrates that the stronger hydroxyl species (OHad) affinity is beneficial to promote the HOR performance. The results indicate that the design of efficient HOR/HER catalyst should focus on the balance between particle size and metallic states.
Mulit-enzyme cascades are a major type of chemical transformations and play a crucial role in biological signal transduction and metabolism. Herein, a trienzyme cascade-triggered fluorescent immunosensor platform was constructed by sequentially integrating alkaline phosphatase (ALP), tyrosinase (TYR) and horseradish peroxidase (HRP). The proposed platform was based on HRP-induced a rapid in situ fluorogenic reaction between dopamine (DA) and 1,5-dihydroxynaphthalene (DHA) to produce a strong yellow azamonardine fluorescent compound (AFC). The obtained AFC was clearly characterized by high-resolution mass spectrum, 1H NMR, 13C NMR and theoretical calculations. The integration of the two-enzyme system (TYR and HRP) or three-enzyme system (ALP, TYR and HRP) led to a maximum of 400.0-fold and 250.0-fold fluorescence enhancements, respectively. Using cardiac troponin Ⅰ (cTnI) as the model antigen, a trienzyme cascade-triggered fluorescent immunosensor platform was developed for quantitative detecting cTnI in a wide linear range from 2 ng/mL to 150 ng/mL with a detection limit of 0.67 ng/mL. In addition, the proposed platform was successfully applied in detection of cTnI in serum of clinical patients. Overall, the developed fluorescent immunosensor performs powerful implications for researching enzyme cascade systems in the field of biomedicine.
Developing highly efficient photocatalysts for selective oxidation of benzene to phenol is of great significance. However, it is still challenging to simultaneously achieve high conversion rate and selectivity. Herein, we demonstrate 99.9% of benzene photoconversion and 99.1% of phenol selectivity under the illumination of AM 1.5 for 12 h. For this purpose, an advanced CuO@CN photocatalyst has been fabricated by loading tubular carbon nitride (CN) with CuO nanoparticles thermally polymerized from Cu-based metal-organic frameworks (MOFs). The sluggish photocharge carrier recombination rate and the excellent stability indicate that the as-prepared nanocomposite is an ideal photocatalyst for benzene oxidation application. This work paves a new avenue for designing novel photocatalyst based on MOFs and carbon nitride materials.
The coevolution and coexistence of bacterial–fungal consortium have been widely reported in various natural ecosystems. The transboundary communication mediated by bacterial acyl–homoserine lactone signals probably is the driving force of fungal spore germination. This study aimed to report a functional bacterial signal molecule, C10-acyl homoserine lactone, which could be sensed by Galactomyces geotrichum. The spore germination rates of G. geotrichum increased by 22%. Meanwhile, carbohydrate production improved by 1.0- to 2.5-fold. G. geotrichum signaled to C10-HSL through receptor gene Rho1 and made a response in cell wall assembly and carbohydrate biosynthesis by the upregulated expression (above 1-fold) of functional genes, such as Smi1, Utr2, and Chs2. It contributed to spore germination and morphology transformation together. This study provides a novel perspective for understating the transboundary cooperation between fungi and bacteria by cell-to-cell communication.
Rechargeable aqueous Zn/MnO2 batteries raise massive research activities in recent years. However, both the working principle and the degradation mechanism of this battery chemistry are still under debate. Herein, we provide an in-depth electrochemical and structural investigation on this controversial issue based on α-MnO2 crystalline nanowires. Mechanistic analysis substantiates a two-electron reaction pathway of Mn2+/Mn4+ redox couple from part of MnO2 accompanying with a reversible precipitation/dissolution of flaky zinc sulfate hydroxide (ZSH) during the discharge/charge processes. The formation of the ZSH layer is double-edged, which passivates the deep dissolution of MnO2 upon discharging, but promotes the electrochemical deposition kinetics of active MnO2 upon charging. The cell degradation originates primarily from the corrosion failure of metallic zinc anode and the accumulation of irreversible ZnMn2O4 phases on the cathode. The addition of MnSO4 to the electrolyte could afford supplementary capacity contribution via electro-oxidation of Mn2+. However, a high MnSO4 concentration will expedite the cell failure by corroding the metallic zinc anodes. The present study will shed a fundamental insight on developing new strategies toward practically viable Zn/MnO2 batteries.
Graphite carbon nitride (g-C3N4) is a promising non-metal photocatalyst for photocatalytic hydrogen production, but its performance is still limited due to sluggish charges separation and low utilization of light. In this work, P-doped and N-doped carbon dots (NCDs) supported g-C3N4 were successfully prepared via hydrothermal and polymerization reactions. The sub-bandgap formed by P-doping enhances the utilization of visible light, and the high electron density of P sites is conducive to the trapping of holes. NCDs also improve light utilization and, more importantly, act as electron acceptors and transporters to promote electron transport. The built-in electric field formed by the synergy of P-doping and NCDs-loading greatly promotes the separation of charges. The PCN/NCDs showed a significantly improved hydrogen evolution activity of 3731 µmol h−1 g−1, which was 6.7 times that of pure carbon nitride (560 µmol h−1 g−1). This strategy may be generalized to the design of g-C3N4 -based photocatalysts, facilitating the separation of charges for enhanced catalytic activity.
Air-breathing proton exchange membrane fuel cells (PEMFCs) are very promising portable energy with many advantages. However, its power density is low and many additional supporting parts affect its specific power. In this paper, we aim to improve the air diffusion and fuel cell performance by employing a novel condensing-tower-like curved flow field rather than an additional fan, making the fuel cell more compact and has less internal power consumption. Polarization curve test and galvanostatic discharge test are carried out and proved that curved flow field can strengthen the air diffusion into the PEMFC and improve its performance. With appropriate curved flow field, the fuel cell peak power can be 55.2% higher than that of planar flow field in our study. A four-layer stack with curved cathode flow field is fabricated and has a peak power of 2.35 W (120 W/kg).
Chiral glycosyl lactone is an important class of bioactive compound and pharmaceutical intermediate in nature, especially for chiral lactones with 4 carbon atoms, which are very useful building blocks for synthesis of biologically interesting compounds. Herein, a selective dehydrogenation and solvent matched catalytic system under oxygen-free conditions was developed to try to achieve the one-step direct conversion of cyclic hemiacetal sugars toward their chiral glycosyl lactones. During the process, the inherent structural characteristics of sugar was efficiently utilized, and the transfer of its chiral centers was realized. Under the optimum condition, the corresponding lactones were successfully prepared from C4-C6 sugars with cyclic hemiacetal structure in acetonitrile. The reaction mechanism in acetonitrile was explored by the first principle density functional theory calculations and tracking reaction process. It was found that the high lactone yield in acetonitrile was due to the high proportion of α-conformation form among multiple tautomers in it. This selective dehydrogenation process may further extend the possibility of the preparation of chiral synthons from carbohydrates directly.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
