近红外二区活体荧光成像在肿瘤诊疗中的应用

由于具备组织穿透深度深和时空分辨率高等优势, 近年来近红外二区(Near-infrared-Ⅱ, NIR-Ⅱ, 1000~1700 nm)荧光成像技术得到了快速发展, 其在肿瘤临床诊断和治疗的潜力更是引发了广泛关注. 本文首先阐释了NIR-Ⅱ窗口荧光成像的原理及其优势, 随后根据结构分类归纳总结了现有荧光团的特征, 重点介绍了荧光探针在性能优化上的进展以及在肿瘤早期检测、 术中导航和光疗中的应用, 最后讨论了现有NIR-Ⅱ 荧光探针的局限以及临床转化面临的挑战, 并对未来的发展方向进行了展望.     

PtRuAgCoNi高熵合金纳米颗粒高效电催化氧化5-羟甲基糠醛

5-羟甲基糠醛(HMF)的电催化氧化被认为是合成2,5-呋喃二甲酸(FDCA)最环保、经济和有效的方法之一,它可作为聚呋喃二甲酸乙二醇酯(PEF)的生物基前体。在这项工作中,我们通过低温溶剂热法合成了PtRuAgCoNi高熵合金纳米颗粒,并在不改变颗粒结构和组成的情况下进行了简易的处理以去除表面活性剂。负载在碳载体上的合金纳米催化剂无论是否含有表面活性剂在HMF电催化氧化为FDCA的过程中都表现出比商业Pt/C更好的催化性能。且表面活性剂的去除可以进一步提高其电催化性能,表明高熵合金纳米粒子在电催化和绿色化学中具有广阔的应用前景。     

Correction to: Derived from Diaryl-λ3-Iodane-Containing Polyoxometalate: Iodine-Doped Molybdenum Carbide for Efficient Electrocatalytic Hydrogen Evolution

Journal of Cluster Science -     

电催化氧化制备2,5-呋喃二甲酸

在第75届联合国大会上,我国承诺力争在2030年前实现碳达峰、2060年前实现碳中和。主要由光合作用产生的生物质将在双碳目标中扮演重要角色,通过高效转化可衍生出一系列替代化石产品的高值化学品。其中,2,5-呋喃二甲酸(FDCA)由于具有与石油基对苯二甲酸(TPA)相似的共轭碳环和二酸结构,可替代TPA用于合成热稳定性能、气体阻隔性能更优的生物基呋喃聚酯,大幅降低聚酯行业对化石资源的严重依赖。此外,FDCA在医药、香料、金属配位化学方面也有广泛应用,从而被认为是12种最具潜力的生物基平台化合物之一。FDCA通常可由5-羟甲基糠醛(HMF)通过催化氧化进行合成。相比于需要贵金属催化剂、高温和高压条件、以化学势作为驱动力的传统热催化方法,电催化氧化采用电极电势作为主要驱动力,是更为绿色和高效的新颖合成方法。本综述对电催化氧化制备FDCA反应所用的贵金属、过渡金属和非金属催化剂进行了总结与分析,梳理了催化剂设计和反应机理的研究脉络,并指出了该领域发展所面临的挑战与机遇。     

Recent Progress in High-Performance Lithium Sulfur Batteries: The Emerging Strategies for Advanced Separators/Electrolytes Based on Nanomaterials and Corresponding Interfaces

Lithium-sulfur (Li−S) batteries, possessing excellent theoretical capacities, low cost and nontoxicity, are one of the most promising energy storage battery systems. However, poor conductivity of elemental S and the “shuttle effect” of lithium polysulfides hinder the commercialization of Li−S batteries. These problems are closely related to the interface problems between the cathodes, separators/electrolytes and anodes. The review focuses on interface issues for advanced separators/electrolytes based on nanomaterials in Li−S batteries. In the liquid electrolyte systems, electrolytes/separators and electrodes system can be decorated by nano materials coating for separators and electrospinning nanofiber separators. And, interface of anodes and electrolytes/separators can be modified by nano surface coating, nano composite metal lithium and lithium nano alloy, while the interface between cathodes and electrolytes/separators is designed by nano metal sulfide, nanocarbon-based and other nano materials. In all solid-state electrolyte systems, the focus is to increase the ionic conductivity of the solid electrolytes and reduce the resistance in the cathode/polymer electrolyte and Li/electrolyte interfaces through using nanomaterials. The basic mechanism of these interface problems and the corresponding electrochemical performance are discussed. Based on the most critical factors of the interfaces, we provide some insights on nanomaterials in high-performance liquid or state Li−S batteries in the future.     

Functional Group Modification and Bonding Characteristics of Ti3C2 MXene-Organic Composites from First-Principles Calculations

The unique physical structure and abundant surface functional groups of MXene make the grafted organic molecules exhibit specific electrical and optical properties. This work reports the results of first-principles calculations to investigate the composite systems formed by different organic molecular monomers, namely acrylic acid (AA), acrylamide (AM), 1-aziridineethanol (1-AD) and glucose, and Ti₃C₂ MXene saturated with different functional groups, namely −OH, −O and −F. The results show that the interaction between organic molecules and the MXene surface depends on the type of functional groups of the organic molecules, while the strength of the interaction is determined by the type of surface functional groups and the number of hydrogen bonds. The bare Ti₃C₂ and Ti₃C₂(OH)₂ can readily form strong chemical and hydrogen bonds with AA and AM molecules, leading to strong adsorption energy and a large amount of charge transfer, while the interaction between organic molecules and MXene saturated by −F or −O groups mainly exhibits physical interactions, accompanied by low adsorption energy and a small amount of charge transfer. This research provides theoretical guidance for the synthesis of high-performance MXene organic composite systems.     

Preparation and Properties of Electrospun Sheath-core Modified-PMMA Nanofibers with Photoluminescence and Photochromic Functions

Multi-functional nanofibers are playing an important role in the optical field, and are widely used in fluorescence indication, product anti-counterfeit identification and smart clothing. Nanofibers with photoluminescence and photochromic functions are already attracting more interest from researchers. In this work, based on electrospun technology, the modified-PMMA nanofibers[PMMA=poly(methyl methacrylate)] with photoluminescence and photochromic functions were prepared through the design of the sheath-core structure(SCNFs 1-4). Compared with other samples, SCNF-4 shows outstanding photoluminescence and photochromic functions. SCNF-4 can produce green light and its fluorescence intensity and fluorescence lifetime can reach 7144 a.u. and 1031.32 μs, respectively. In photochromic functions, SCNF-4 can show purple in 1 min under the 365 nm ultraviolet light, and the color can be preserved for more than 4 h under the sunlight. When SCNF-4 is irradiated by far infrared light, the color of the samples can fade quickly in 40 s. Under the irradiation of ultraviolet light of different wavelengths, SCNF-4 can display multi-color fluorescence and achieve a reversible transition between white and purple. The design of the sheath-core structure realizes the complementarity of photoluminescence and photochromic functions of the electrospun modified-PMMA nanofibers, which is important to promote the wide application of multi-functional nanofibers in the optical field.     

Amorphous Carbon Film with Self-modified Carbon Nanoparticles Synthesized by Low Temperature Carbonization of Phenolic Resin for Simultaneous Sensing of Dopamine and Uric Acid

A self-modified film electrode consisting of homogeneous snowflake-shaped nanoparticles on the amorphous carbon substrate (HNAC) was prepared by low temperature carbonization of phenolic resin. Such a unique structure was beneficial to enhance the electroanalysis signal responds. Simultaneous detection of DA and UA was performed on the HNAC using differential pulse voltammetry (DPV) at pH 8 phosphate buffer. The well-defined oxidation peak potential separation reached 260 mV between DA and UA. Meanwhile, the detection limit of HNAC were 0.401 μM (DA) and 2.800 μM (UA).     

Efficient electrochromic device based on sol–gel prepared WO<Subscript>3</Subscript> films

Tungsten oxide (WO₃) films were prepared on indium–tin oxide (ITO) glass by sol–gel method. The influence of annealing temperature on the structural, morphological, optical, electrochemical, and electrochromic properties has been investigated. The film annealed at 250 °C with an amorphous structure exhibits a noticeable electrochromic performance, such as the highest optical modulation of 58.5 % at 550 nm, high electrochemical stability, and excellent reversibility (Q _b/Q _c?=?96.3 %). An electrochromic (EC) device based on WO₃/NiO complementary structure shows improved performance. It exhibits high optical transmittance modulation of 62 % at 550 nm, excellent cycling stability, and relatively fast electrochromic response time (10 s for coloration and 19 s for bleaching).     

Synthesis and Reactivity of Mononuclear Iron Models of [Fe]‐Hydrogenase that Contain an Acylmethylpyridinol Ligand

[Fe]‐hydrogenase has a single iron‐containing active site that features an acylmethylpyridinol ligand. This unique ligand environment had yet to be reproduced in synthetic models; however the synthesis and reactivity of a new class of small molecule mimics of [Fe]‐hydrogenase in which a mono‐iron center is ligated by an acylmethylpyridinol ligand has now been achieved. Key to the preparation of these model compounds is the successful C?O cleavage of an alkyl ether moiety to form the desired pyridinol ligand. Reaction of solvated complex [(2‐CH₂CO‐6‐HOC₅H₃N)Fe(CO)₂(CH₃CN)₂]⁺(BF₄)^? with thiols or thiophenols in the presence of NEt₃ yielded 5‐coordinate iron thiolate complexes. Further derivation produced complexes [(2‐CH₂CO‐6‐HOC₅H₃N)Fe(CO)₂(SCH₂CH₂OH)] and [(2‐CH₂CO‐6‐HOC₅H₃N)Fe(CO)₂(CH₃COO)], which can be regarded as models of FeGP cofactors of [Fe]‐hydrogenase extracted by 2‐mercaptoethanol and acetic acid, respectively. When the derivative complexes were treated with HBF₄?Et₂O, the solvated complex was regenerated by protonation of the thiolate ligands. The reactivity of several models with CO, isocyanide, cyanide, and H₂ was also investigated.