Latest ArticlesLabel-free immunoassay is confronted with a great challenge that its insufficient sensitivity for low concentration analytes, which can be assigned to the low catalytic efficiency of modified materials towards electroactive molecules. Herein, a universal MOF nanozyme-induced catalytic amplification strategy was proposed for constructing highly sensitive label-free electrochemical immunoassay. Specifically, the synthesized CuFe-MOF nanozyme with superior peroxidase (POD)-like activity, regarding as a MOF nanozyme model, can catalyze hydrogen peroxide to produce hydroxyl radicals (•OH), which can efficiently oxidize electroactive probe (such as 1,2-phenylenediamine (o-PD)) accompanying with intense electrochemical signals. Modification of MOF nanozyme on the electrode and capture of antibodies for binding target antigens hinder the catalytic process of MOF nanozyme toward o-PD, resulting in a gradual decrease in electrochemical signal with increasing target antigen concentration, enabling quantitative label-free immunoassay. Thus, a highly sensitive label-free immunosensor using MOF nanozyme-induced catalytic amplification achieved effective detection of Immunoglobulin G (IgG) with a wide linear range of 0.001–50 ng/mL and low detection limit of 0.45 pg/mL. This work proposes a promising nanozyme-induced catalytic amplification strategy for the development of label-free electrochemical immunoassay.
A series of novel crown aldoxime ethers were synthesized, demonstrating notable thermal and hydrolysis stability. The showcased acid-catalyzed and photo-induced cis/trans isomerization, which enables orthogonal control over both guest complexation and the chiroptical effects of these crown aldoxime ethers, manifesting a regulation of complexation through isomerization at binding heteroatoms.
Rechargeable magnesium ion batteries (RMBs) are investigated as lithium-ion batteries (LIBs) alternatives owing to their favorable merits of high energy density, abundance and low expenditure of Mg, as well as especially non-toxic safety and low risk of dendrite formation in anodes, which endows them to be more easily assembled in electric-power vehicles for the extended application of civilian-military fields. Nevertheless, the high charge density, strong polarization effect, and slow diffusion kinetics of Mg2+ remain a large obstacle and thus enormous efforts have to be paid to mend the gap with commercial demand for cathode materials. At present, RMBs cathode materials mainly contain transition metal sulfides/oxides, polyanionic compounds and Prussian blue analogs, and several methods such as nano structuring, doping regulation and coating modification have been applied to materials design for better performance. In this paper, the current research status of RMBs cathode materials at home & abroad is arranged and summarized along with challenges of development in the future focusing on synthesis of RMBs cathode materials with high energy density as well as satisfactory cycling performance. And this analysis aims to provide reference and basis for researchers working on RMBs technology advancement.
Constructing more stable self-assembled organic nanotubes has been one of the focuses of scientists in recent decades. Hexakis(m-phenylene ethynylene) (m-PE) benzene macrocycles can form stable tubular self-assemblies in nonpolar or weakly polar solvents through the π-π interaction of the main skeleton and the hydrogen bonding of the side chain amide. We covalently linked two macrocyclic units at the para position of the macrocycles using two oligo(β-alanine) linkers through an efficient synthetic route. UV–visible spectroscopy, fluorescence spectroscopy, and circular dichroism spectroscopy were employed to demonstrate that the incorporation of two peptide chains significantly enhances the stability of the self-assemblies. Meanwhile, the average open time of the ion channel formed by the macrocyclic dimer in the lipid bilayer was significantly better than that of the ion channel formed by a single macrocycle. This study shows that this strategy effectively improves the efficiency of self-assembly and the stability of its formed self-assemblies, providing a feasible strategy for constructing organic self-assembled nanotubes in highly polar solvents.
A photocatalyst-free visible-light-promoted three-component reaction of thianthrenium salts, isothiocyanates, and amines is presented, which affords a rapid and efficient approach to S-arylisothioureas under mild conditions. This developed method exhibits the advantages of readily available raw materials, broad substrate scope, good functional tolerance, and operational simplicity. It is worth mentioning that the byproduct thianthrene can be recycled in quantity, ultimately maximizing the atomic economy of the reaction and avoiding chemical waste. Mechanism investigations support the strategy involving a photoinduced EDA complex.
Reactive oxygen species (ROS) are essential in various pathological and physiological processes. Developing nanosystems that generate ROS in a controlled manner is of great interest for nanomedicine. DNA nanotechnology offers a promising approach to constructing programmable ROS-generating platforms. By incorporating photosensitizers or metal ions, DNA nanostructures can be designed to produce ROS in a spatially and temporally desired fashion. DNA-based ROS-generating nanosystems hold great potential in intracellular homeostasis regulation, drug release, and cancer therapy. This review summarizes recent advances in developing DNA-based ROS-generating nanosystems, highlights their emerging biomedical applications, and discusses the opportunities and challenges for further applications. DNA nanotechnology provides a versatile toolkit to construct biocompatible ROS-generating platforms for next-generation nanomedicines.
In electrochemical energy devices, the operating conditions always exert enormous influence on electrocatalysts' performances. Phosphoric acid (PA), acted as the proton carriers, can be adsorbed on Pt surface, block active sites and affect the electronic structure of Pt unfavorably, which severely restricts the performance of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). Herein, simply basic organic compounds, such as dicyandiamide (DCD), melamine (Mel) and cyanuric acid (CA), are decorated on Pt surface (DCD-Pt/C, Mel-Pt/C and CA-Pt/C) to induce the adsorption transfer of proton carriers. The decoration can not only inject electrons to Pt and enhance oxygen reduction reaction (ORR) activity but also can induce PA to transfer from Pt surface to organic compounds, decontaminating active sites. In addition, the organic compounds with the larger conjugated system and the smaller electronegativity of ligating atoms would have a greater interaction with Pt, causing a larger decoration amount on Pt surface, which leads to more excellent ORR activity and resistance to PA blockage effect. Therefore, Mel-Pt/C shows a peak power density of 629 mW/cm2, exceeding commercial Pt/C (437 mW/cm2), DCD-Pt/C (539 mW/cm2) and CA-Pt/C (511 mW/cm2) with the same loading.
Lithium–sulfur (Li–S) batteries are considered one of the most promising next-generation secondary batteries owing to their ultrahigh theoretical energy density. However, practical applications are hindered by the shuttle effect of soluble lithium polysulfides (LiPSs) and sluggish redox kinetics, which result in low active material utilization and poor cycling stability. Various copper-based materials have been used to inhibit the shuttle effect of LiPSs, owing to the strong anchoring effect caused by the lithiophilic/sulphilic sites and the accelerated conversion kinetics caused by excellent catalytic activity. This study briefly introduces the working principles of Li–S batteries, followed by a summary of the synthetic methods for copper-based materials. Moreover, the recent research progress in the utilization of various copper-based materials in cathodes and separators of Li–S batteries, including copper oxides, copper sulfides, copper phosphides, copper selenides, copper-based metal-organic frameworks (MOFs), and copper single-atom, are systematically summarized. Subsequently, three strategies to improve the electrochemical performance of copper-based materials through defect engineering, morphology regulation, and synergistic effect of different components are presented. Finally, our perspectives on the future development of copper-based materials are presented, highlighting the major challenges in the rational design and synthesis of high-performance Li–S batteries.
Zeolitic imidazolate frameworks (ZIFs) are a series of materials composited by metal ions and organic ligands with high specific surface area, which might be great precursors to produce metal oxides by calcination for gas sensor application. However, Zn-ZIF (ZIF-8) is hard to transform as ZnO in air and keeping the unique framework simultaneously. In this work, Fe2+ was introduced into the metal node to replace a part of Zn2+ ions, and it could be oxidized as Fe3+ in the calcination to facilitate the oxidation process of the 2-methylimdazole ligands to give Fe-ZnO complex shell with high specific surface area (108 m2/g) and abundant oxygen vacancies (48%). The micro electro mechanical systems (MEMS) sensor based on the 6%-Fe-ZnO complex shell performed outstanding gas sensing properties to the low-concentration acetone vapor, including high response (ΔR/Rg = 11.2 to 5 ppm acetone), superior selectivity (Sacetone/Sethanol = 5.6) and fast response speed (τres = 2.6 s). This work not only provided the research of an exceptional acetone MEMS sensor, but also induced a strategy to produce metal oxide derived from ZIFs with complex structures for the universal synthesis methodology.
In 2023, The MOE Key Laboratory of Macromolecular Synthesis and Functionalization in Zhejiang University had achieved several important results in the five research directions. First, for controllable catalytic polymerization, a new silicon-centered organoboron binary catalyst was developed for copolymerization of epoxides, and a series of cooperative organocatalysts were proposed for ring-opening copolymerization of chalcogen-rich monomers. Second, with respect to microstructure and rheology, axially encoded metafiber demonstrated its capacity for integrating multiple electronics, while artificial nacre materials showed improved strength and toughness due to interlayer entanglement. Third, concerning separating functional polymers, interfacial polymerization was monitored via aggregation-induced emission, and vacuum filtration was applied to assist interfacial polymerization. Fourth, in terms of biomedical functional polymers, we designed antibacterial materials such as a novel quaternary ammonium salt that enables polyethylene terephthalate recycling and its antibacterial function, nanozyme-armed phage proved its efficiency in combating bacterial infection, and also transition metal nanoparticles showed capacities in antibacterial treatments. We also made achievements in biomedical materials, including polymeric microneedles for minimally invasive implantation and functionalization of cardiac patches, as well as ROS-responsive/scavenging prodrug/miRNA balloon coating to promote drug delivery efficiency. Besides, methods and mechanisms of RNA labeling has been developed. Fifth, about photo-electro-magnetic functional polymers, through-space conjugation was successfully manipulated by altering subunit packing modes, room-temperature phosphorescent hydrogels were synthesized via polymerization-induced crystallization of dopant molecules, and single crystals of both fullerene and non-fullerene acceptors were grown in crystallized organogel, with their photodetection performance further explored. The related works are reviewed in this paper.