MXene介导的近红外光热效应用于快速清除多种耐药菌以及菌膜

随着细菌耐药性的不断出现和加重,针对耐药菌感染和菌膜这类难以用传统抗生素治疗的临床医疗问题,需要发展新型高效快速的杀菌方法.本文采用新型二维材料MXene与近红外激光相结合,实现了在20 min内对细菌以及菌膜的快速高效杀除.为了测试该方案的广谱抗菌性,我们对包括耐药性的耐甲氧西林金黄色葡萄球菌(MRSA)和耐万古霉素...     

MXenes的制备、性质及其在肿瘤诊疗中的研究进展

二维过渡金属碳化物、氮化物或碳氮化物(MXenes)已成为二维材料中一个新兴的热点领域。MXenes材料具有优异的电子传递性能、出色的光热转换性能、较高的比表面积、良好的生物相容性和低毒性等特点, 在肿瘤诊疗中显示出良好的应用前景。本文简要总结了MXenes的制备方法, 包括氢氟酸法、氟盐法、熔融盐法、碱辅助水热法和化学气相沉积法, 及其稳定性、机械性质、光学性质和电学性质。重点综述了MXenes在肿瘤诊疗中的应用, 包括光热治疗、多模式联合治疗、构建MXenes表面介孔材料的联合治疗和MXenes主动靶向联合治疗, 以及建立MXenes诊断-治疗一体化平台。最后简要介绍了MXenes可能辅助肿瘤诊疗的其他特性及其应用, 并阐述了MXenes在肿瘤诊疗中存在的挑战以及未来发展前景。     

新型二维层状纳米材料的抗菌研究进展

近年来,抗生素耐药菌在全球范围内得到迅速而广泛地传播,新型抗菌药物的开发刻不容缓。随着生物纳米技术的发展,二维层状纳米材料有望成为处理耐药菌的替代选择。本文综述了石墨烯及其衍生物(GMs)、过渡金属硫化物(TMDs)、层状双氢氧化物(LDHs)及MXenes二维层状纳米材料的结构特征及其抗菌应用的最新报道,讨论了材料的抗菌机制,例如物理/机械损伤、脂质提取、氧化应激和光热/光动力效应等。最后,本文针对二维层状纳米材料的抗菌应用前景进行了展望:(1)材料特有的空间结构及优异的生物相容性决定了其可以作为抗菌药物的理想载体;(2)优异的光动力和光热杀菌效应使它具有治疗局部皮肤感染的强大潜力;(3)拥有光催化抗菌特性的2D材料可制成抗菌涂层,实现简易的原位消毒,有望应用于无菌医疗设备中。     

Current state of the art on tailoring the MXene composition,structure, and surface chemistry

MXenes constitute a family of two-dimensional transition metal carbides, carbonitrides and nitrides. Discovered in 2011, the number of MXenes has expanded significantly and more than 20 different MXenes have been synthesized, with many more predicted from theoretical calculations. MXenes constitute an exceptional family of materials based on their availability for elemental alloying and control of surface terminations, which enables synthesis of a range of structures and chemistries. Consequently, the MXenes exhibit an unparalleled potential for tuning of the materials properties for a wide range of applications. At present, MXenes have emerged with astonishing electronic, optical, plasmonic and thermoelectric properties. This has resulted in a global surge of research around a wide variety of applications, including but not limited to energy storage, carbon capture, electromagnetic interference shielding, reinforcement for composites, water filtering, sensors, and photo-, electro- and chemical catalysis etc. In this review, we present the available state of the art tailoring of the MXene properties owing to recent advances in structural ordering and tuning of surface terminations.     

Recent advances in MXenes: From fundamentals to applications

The family of MAX phases and their derivative MXenes are continuously growing in terms of both crystalline and composition varieties. In the last couple of years, several breakthroughs have been achieved that boosted the synthesis of novel MAX phases with ordered double transition metals and, consequently, the synthesis of novel MXenes with a higher chemical diversity and structural complexity, rarely seen in other families of two-dimensional (2D) materials. Considering the various elemental composition possibilities, surface functional tunability, various magnetic orders, and large spin–orbit coupling, MXenes can truly be considered as multifunctional materials that can be used to realize highly correlated phenomena. In addition, owing to their large surface area, hydrophilicity, adsorption ability, and high surface reactivity, MXenes have attracted attention for many applications, e.g., catalysts, ion batteries, gas storage media, and sensors. Given the fast progress of MXene-based science and technology, it is timely to update our current knowledge on various properties and possible applications. Since many theoretical predictions remain to be experimentally proven, here we mainly emphasize the physics and chemistry that can be observed in MXenes and discuss how these properties can be tuned or used for different applications.     

The Antibacterial Applications of Graphene and Its Derivatives

Graphene materials have unique structures and outstanding thermal, optical, mechanical and electronic properties. In the last decade, these materials have attracted substantial interest in the field of nanomaterials, with applications ranging from biosensors to biomedicine. Among these applications, great advances have been made in the field of antibacterial agents. Here, recent advancements in the use of graphene and its derivatives as antibacterial agents are reviewed. Graphene is used in three forms: the pristine form; mixed with other antibacterial agents, such as Ag and chitosan; or with a base material, such as poly (N‐vinylcarbazole) (PVK) and poly (lactic acid) (PLA). The main mechanisms proposed to explain the antibacterial behaviors of graphene and its derivatives are the membrane stress hypothesis, the oxidative stress hypothesis, the entrapment hypothesis, the electron transfer hypothesis and the photothermal hypothesis. This review describes contributions to improving these promising materials for antibacterial applications.     

MXene Printing and Patterned Coating for Device Applications

As a thriving member of the 2D nanomaterials family, MXenes, i.e., transition metal carbides, nitrides, and carbonitrides, exhibit outstanding electrochemical, electronic, optical, and mechanical properties. They have been exploited in many applications including energy storage, electronics, optoelectronics, biomedicine, sensors, and catalysis. Compared to other 2D materials, MXenes possess a unique set of properties such as high metallic conductivity, excellent dispersion quality, negative surface charge, and hydrophilicity, making them particularly suitable as inks for printing applications. Printing and pre/post-patterned coating methods represent a whole range of simple, economically efficient, versatile, and eco-friendly manufacturing techniques for devices based on MXenes. Moreover, printing can allow for complex 3D architectures and multifunctionality that are highly required in various applications. By means of printing and patterned coating, the performance and application range of MXenes can be dramatically increased through careful patterning in three dimensions; thus, printing/coating is not only a device fabrication tool but also an enabling tool for new applications as well as for industrialization.     

二维过渡金属碳氮化合物的生物医学应用

二维过渡金属碳化物、氮化物及碳氮化合物(MXenes)是一类新兴的二维纳米材料.由于其独特的光、电、磁、热等物理化学性能,MXenes二维材料被广泛应用到能源储备、环境监测、化学催化等领域.由于其大的比表面积、优异的近红外吸收和组分可调换等性质,近年来在生物医学方面也得到了快速的发展.简要介绍了MXenes二维纳米材料...     

Theranostic 2D Tantalum Carbide (MXene)

The large‐dimensional and rigid ceramic bulks fabricated by high‐temperature solid‐phase reaction and sintering have never been considered for possibly entering and circulating within the blood vessels for biomedical applications, especially on combating cancer. Here, it is reported for the first time that MAX ceramic biomaterials exhibit unique functionalities for dual‐mode photoacoustic/computed tomography imaging and are highly effective for in vivo photothermal ablation of tumors upon being exfoliated into ultrathin nanosheets within atomic thickness (MXene). As a paradigm, 2D ultrathin tantalum carbide nanosheets (Ta₄C₃ MXenes) with nanosized lateral sizes are successfully synthesized based on a two‐step liquid exfoliation strategy of MAX phase Ta₄AlC₃ by combined hydrofluoric acid (HF) etching and probe sonication. The structural, electronic, and surface characteristics of the as‐exfoliated nanosheets are revealed by various characterizations combined with first‐principles calculations via density functional theory. Especially, the superior photothermal‐conversion performance (efficiency η of 44.7%) and in vitro/in vivo photothermal ablation of tumor by biocompatible soybean phospholipid‐modified Ta₄C₃ nanosheets are systematically revealed and demonstrated. Based on the large family members of MXenes, this work may offer a paradigm that MXenes can achieve the specific biomedical applications (here, theranostic) providing that their compositions and nanostructures are carefully tuned and optimized to meet the strict requirements of biomedicine.     

Plasma-modified biomaterials for self-antimicrobial applications

The surface compatibility and antibacterial properties of biomaterials are crucial to tissue engineering and other medical applications, and plasma-assisted technologies have been employed to enhance these characteristics with good success. Herein, we describe and review the recent developments made by our interdisciplinary team on self-antimicrobial biomaterials with emphasis on plasma-based surface modification. Our results indicate that a self-antibacterial surface can be produced on various types of materials including polymers, metals, and ceramics by plasma treatment. Surface characteristics such as roughness, microstructure, chemistry, electronegativity, free energy, hydrophilicity, and interfacial physiochemistry are important factors and can be tailored by using the appropriate plasma-assisted processing parameters. In particular, mechanistic studies reveal that the interfacial physiochemical processes, biocidal agents, and surface free energy are predominantly responsible for the antibacterial effects of plasma-modified biomaterials.     

Electrocatalytic/photocatalytic properties and aqueous media applications of 2D transition metal carbides (MXenes)

The 2D transition metal carbides (MXenes) are increasingly considered among of the most promising 2D nanomaterials, because of their unique properties such as hydrophilic nature, metallic conductivity, large surface-area-to-volume ratio, and active surface functionalities. This has led to their growing utilization in water/wastewater treatment and environmental remediation applications, including water purification membranes, heavy metal removal, capacitive deionization, and bactericidal agents. This account will focus on the key characteristic properties of MXenes such as high metallic/electronic conductivity, and catalytic activity, and their utilization for the electrocatalytic and photocatalytic-based environmental remediation applications. We will also address the key challenges facing MXene-based materials in aqueous media and possible mitigation routs.     

Surface Modified MXene‐Based Nanocomposites for Electrochemical Energy Conversion and Storage

In recent years, the rapidly growing attention on MXenes makes the material a rising star in the 2D materials family. Although most researchers' interests are still focused on the properties of bare MXenes, little attention has been paid to the surface chemistry of MXenes and MXene‐based nanocomposites. To this end, this Review offers a comprehensive discussion on surface modified MXene‐based nanocomposites for energy conversion and storage (ECS) applications. Based on the structure and reaction mechanism, the related synthesis methods toward MXenes are briefly summarized. After the discussion of existing surface modification techniques, the surface modified MXene‐based nanocomposites and their inherent chemical principles are presented. Finally, the application of these surface modified nanocomposites for supercapacitors (SCs), lithium/sodium–ion batteries (LIBs/SIBs), and electrocatalytic water splitting is discussed. The challenges and prospects of MXene‐based nanocomposites for future ECS applications are also presented.     

Surface Nanopore Engineering of 2D MXenes for Targeted and Synergistic Multitherapies of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and deadly gastrointestinal malignancies. Given its insensitivity to traditional systematic chemotherapy, new therapeutic strategies for efficient HCCs treatment are urgently needed. Here, the development of a novel 2D MXene‐based composite nanoplatform for highly efficient and synergistic chemotherapy and photothermal hyperthermia against HCC is reported. A surface‐nanopore engineering strategy is developed for the MXenes’ surface functionalization, which achieves the uniform coating of a thin mesoporous‐silica layer onto the surface of 2D Ti₃C₂ MXene (Ti₃C₂@mMSNs). This strategy endows MXenes with well‐defined mesopores for on‐demand drug release/delivery, enhanced hydrophilicity/dispersity, and abundant surface chemistry for targeting engineering. Systematic in vitro and in vivo evaluations have demonstrated the high active‐targeting capability of arginine‐glycine‐aspartic acid (RGD)‐targeting Ti₃C₂@mMSNs into tumor, and the synergistic chemotherapy (contributed by the mesoporous shell) and photothermal hyperthermia (contributed by the Ti₃C₂ MXene core) completely eradicate the tumor without obvious reoccurrence. This work not only provides a novel strategy for efficiently combating HCC by developing MXene‐based composite nanoplatforms, but also paves a new way for extending the biomedical applications of MXenes by surface‐nanopore engineering.     

Emerging applications of MXenes for photodetection: Recent advances and future challenges

The development and applications of transition metal carbides, nitrides and carbonitrides, commonly denoted as MXenes, have during the last few years rapidly expanded in various technological fields owing to their unique and controllable properties. These materials exhibit competing performance comparing with traditional materials and have created numerous opportunities for technology markets. Taking the advantage of excellent optoelectronic features, MXenes have been utilized for the construction of photodetectors with various structures and unique functionalities. While the application of MXenes in this area can be traced back to 2016, we have during the recent three years witnessed a dramatic development of MXene-based photodetectors, calling for a timely review to guideline their future direction. In this work, synthetic strategies of pristine MXenes are briefly introduced and their properties are discussed focusing on the optoelectronic aspects that are fundamental for the photoelectric conversion. Recent advances of MXene-based photodetectors are comprehensively summarized based on different types of MXenes and innovative designs of device construction. Finally, we provide perspectives for future challenges and opportunities of MXene-based photodetectors, which may enlighten their further development.     

Ti基MXene及其复合材料在金属离子电池中的进展

二维过渡金属碳(氮或碳氮)化物MXene自2011年首次报告后,其家族成员不断增加,目前已有超过20种MXene被成功合成。凭借独特的层状结构,出色的物理化学性质和可设计的表面官能团特性,MXene被认为是极具潜力的电极材料。近年来,MXene及其复合材料在储能领域进展显著。为此,本文综述了Ti基MXene及其复合材料在Li离子电池和Na离子电池中的研究进展,并结合其制备方法和特性,详细介绍了电池性能提升策略或机制。最后,指出了MXene及其复合材料构建高性能电池面临的挑战,并对未来前景进行了展望。      

Mechanotribological Aspects of MXene-Reinforced Nanocomposites

MXenes are recently discovered 2D nanomaterial with superior mechanical, thermal, and tribological properties, being commonly employed in a wide variety of critical research areas, ranging from cancer therapy to energy and environmental applications. Due to their special properties, such as mechanoceramic nature with excellent mechanical performance, thermal stability and rich surface properties, MXenes have tremendous potential as advanced composite structures, especially those based on polymers due to a great affinity between macromolecules and the terminating groups of 2D MXenes. MXenes have been extensively explored in metal matrix nanocomposites as well as in solid- or liquid-based lubrication systems owing to the 2D structure and antifriction characteristics. The purpose of the this paper is to provide a comprehensive insight into the material, mechanical, and tribological properties of the MXene nanolayers with discussions on the recent advancements attained from MXene-reinforced nanocomposites starting with the synthesis, fabrication techniques, intricacies of the underlying physics and mechanisms, and finally focusing on the progress in computational studies. This analysis of MXene-based composites will stimulate an emerging field with innumerable opportunities and ample potentials to produce newfangled materials and structures with targeted properties.     

2D Transition Metal Carbides (MXenes): Applications as an Electrically Conducting Material

Since their discovery in 2011, 2D transition metal carbides, nitrides, and carbonitrides, known as MXenes, have attracted considerable global research interest owing to their outstanding electrical conductivity coupled with light weight, flexibility, transparency, surface chemistry tunability, and easy solution processability. Here, the promising abilities of 2D MXenes, from both experimental and theoretical perspectives, for designing conductive materials for a range of applications, including electromagnetic interference shielding, flexible optoelectronics, sensors, and thermal heaters, are presented.     

MXene-based nanomaterials as adsorbents for wastewater treatment: a review on recent trends

The wastewater treatment is a challenging research area to reduce the increasing pressure on limited fresh water resources. Amongst several techniques adopted and practiced, adsorption is one of the most effective and sustainable eco-friendly processes. In recent years, MXene nanomaterials, a new family of transition metal carbides, have gained increasing attention as the potential adsorbent for pollutants due to their unique features such as large surface area with abundant active sites and hydrophilicity. A wide range of pollutants viz. heavy metal ions, organic dyes, radionuclides, and toxic gas molecules have been sensed by 2D MXenes. An inclusive understanding on the adsorptive behavior of MXene-based materials is needed to explain the removal mechanism and effects of different adsorption parameters. This review gives a general overview on recent research progress on MXene materials with special reference to their applications for the adsorptive removal of different pollutants. The general trends in the synthesis of MXenes, their stability and different factors affecting the adsorption process along with the main challenges in understanding the full potential of MXenes for environmental applications are discussed.     

Metal‐Containing Polydopamine Nanomaterials: Catalysis,Energy, and Theranostics

Polydopamine (PDA) is a major type of artificial melanin material with many interesting properties such as antioxidant activity, free‐radical scavenging, high photothermal conversion efficiency, and strong metal‐ion chelation. The high affinity of PDA to a wide range of metals/metal ions has offered a new class of functional metal‐containing polydopamine (MPDA) nanomaterials with promising functions and extensive applications. Understanding and controlling the metal coordination environment is vital to achieve desirable functions for which such materials can be exploited. MPDA nanomaterials with metal/metal ions as the active functions are reviewed, including their synthesis and metal coordination environment and their applications in catalysis, batteries, solar cells, capacitors, medical imaging, cancer therapy, antifouling, and antibacterial coating. The current trends, limitations, and future directions of this area are also explored.