贵金属基纳米酶的研究进展

贵金属纳米材料在纳米尺度具有独特的光学、 电学性质及优异的催化性能, 是一类重要的功能纳米材料. 基于贵金属材料的纳米酶研究是贵金属纳米材料在生物医学领域的一个前沿研究方向. 贵金属基纳米酶具有特殊的光学性质、 较好的化学稳定性、 可调控的类酶活性及良好的生物相容性, 是目前纳米生物医学领域的热点研究材料. 本文总结了贵金属基纳米酶的活性种类、 活性机理、 活性调控以及在生物医学等领域的潜在应用.     

基于金属有机框架的纳米酶及其在生物分析中的应用

纳米酶是一类具有类酶活性的纳米材料,在分析化学和疾病诊疗领域具有良好的发展潜力。金属有机框架（MOFs）材料是由金属节点和有机配体形成的多孔晶体材料,其结构与天然酶有一定的相似性。目前,研究者已经开发了多种基于MOFs的纳米酶,包括具有类过氧化物酶、类氧化酶、类超氧化物歧化酶和类水解酶活性的纳米酶等,并显示出广阔的应用前景。本文根据材料的结构特点,将基于MOFs的纳米酶分为原始MOFs、化学修饰MOFs、MOFs复合材料和MOFs衍生物4类,介绍了这4类纳米酶制备的基本原理与最新研究进展。在此基础上,根据比色传感、荧光传感和电化学传感等分析策略,综述了MOFs基纳米酶在生物分析方面的研究和应用进展,讨论了其在实际应用中所面临的挑战和未来的发展趋势。     

纳米通道内酶组装及其催化反应研究进展

研究酶的组装和催化反应不仅有利于探索生命活动的本质,同时对开发酶在工业合成、分析检测、疾病治疗等领域的实际应用价值具有重要的指导意义. 研究发现,酶的有效固定和有序组装是保持酶活性、酶促反应的稳定性和对酶催化过程进行控制的重要途径,而在纳米通道内进行单酶或多酶的有序组装,利用纳米通道的限域效应可有效保持酶的构型进而提高酶催化反应的选择性和催化效率,增强酶级联反应的动力学进程. 本文概述了近年来基于纳米通道的酶反应器在生物传感领域的研究进展,着重描述纳米通道限域空腔内酶的组装方法、酶催化反应及其动力学机制,并展望了基于纳米通道的酶反应器的应用前景.     

纳米酶及其分析检测应用研究进展

在纳米材料基础上诞生的纳米酶推动了化学、材料学以及生物学等学科的发展。纳米酶克服了天然酶的许多缺点,如价格昂贵、易失活和储存条件要求苛刻等,对生物传感、免疫分析、癌症诊断和治疗等领域产生了巨大的影响。 本论文主要介绍了迄今发现的纳米酶种类、纳米酶调控方式以及纳米酶在分析检测中的应用进展。 此外,针对纳米酶未来发展方向提出了一些思考和建议。     

纳米酶在抗肿瘤治疗中的应用

纳米酶是一类具有天然酶活性的纳米材料。相对于天然酶，纳米酶有着制备简单，成本低，稳定性高，易于保存等优点。自从2007年，我国科学家阎锡蕴院士首次发现Fe3O4纳米颗粒具有类过氧化物酶活性以来，对纳米酶的研究迅速崛起。纳米酶能够通过模拟天然酶，在生理环境或体内实现催化反应，改善肿瘤微环境，并通过产生活性氧实现肿瘤治疗。     

载酶纳米催化体系用于疾病诊疗的研究进展

酶作为一种具有高度特异性和高效性的催化剂, 可在细胞器中通过复杂有序的生化反应调节细胞的代谢过程. 受细胞区隔化结构的启发, 仿生设计纳米酶催化体系、 构筑限域酶催化微环境从而提高酶催化活性的研究为酶催化应用开辟了新思路. 纳米催化体系保留了小尺寸、 大比表面积、 肿瘤部位选择性富集等优势, 在疾病的诊疗方面发挥了巨大的优势. 本文首先总结了天然酶、 模拟酶和级联酶体系的催化机理, 对仿生构筑的纳米酶催化材料的载体体系进行了概述, 介绍了纳米酶催化体系在生物成像方面的应用, 讨论了其在相关代谢类疾病的作用途径, 并对纳米酶催化体系用于生物诊疗的发展前景进行了展望.     

纳米酶：一种新型的生物安全材料

纳米酶,是一类自身蕴含酶学特性的纳米材料。自2007年被首次报道以来,已有近千种不同组成的纳米材料被发现具有类酶活性,它们表现出类似天然酶的酶促反应动力学和催化机理,并且可以作为天然酶的替代物进行应用。纳米酶本身所具有的类酶活性及其多功能、经济、稳定和易于大批量生产的优势,使其在病原微生物的快速检测以及感染性疾病的预防和治疗中展现出良好的应用潜力。因此,纳米酶被视为一种新型的生物安全材料。本文对近年来纳米酶在检测和杀灭细菌、病毒等病原微生物中的应用进行综述,为应对重大生物安全威胁和防范生物安全危害时,开发基于纳米酶的诊断和抗病原微生物治疗策略提供依据。     

纳米花型酶-无机杂化固定化酶研究进展

酶是一种绿色高效的生物催化剂,被广泛地应用于工业生产中,为了更好的提升游离酶的性能,酶固定化技术应运而生。然而,与游离酶相比,固定化酶活性下降以及传质受限一直是酶固定化技术亟待解决的关键问题。作为一种新型酶固定化技术,纳米花型酶-无机杂化固定化酶因具有高比表面积、高酶活性和高催化效率,且制备简单,绿色无污染受到广泛关注。本文综述了近年来纳米花型酶-无机杂化固定化酶的研究进展,根据纳米花型酶-无机杂化固定化酶的形成特点,将其分为单酶纳米花、双酶纳米花和负载型纳米花。阐述了纳米花型酶-无机杂化固定化酶的制备过程和形成机理并对纳米花型酶-无机杂化固定化酶在食品工业和检测领域的应用进展做出总结。最后,对纳米花型酶-无机杂化固定化酶的发展前景做出展望。     

单原子纳米酶在生物医学中的应用

新近发展的单原子纳米酶(SAzymes),兼具纳米材料与酶的特性,可以精确模仿天然酶结构,在生物传感、疾病治疗等领域有着广泛的应用。SAzymes具有均匀分散的单原子结构和良好的配位环境,表现出显著的催化活性和稳定性。本文综述了近年来SAzymes在生物医学领域的应用,包括生物传感、肿瘤治疗、抗菌和抗氧化,并展望了SAzymes未来的发展,为合理设计多功能SAzymes提供了可行策略。     

锰-铜双金属层状硅酸盐纳米酶的构筑及类酶活性

采用一步溶胶凝胶法, 在室温下合成了一种含有锰、 铜的双金属层状硅酸盐(AMCP), 并探究了其类漆酶和类过氧化物酶活性. 结果表明, AMCP具有与天然黏土类似的层状结构, 且结构中多价态的锰和铜使其具有优异的类漆酶和类过氧化物酶活性. 此外, 与天然酶相比, AMCP在极端温度和pH值下具有更强的耐受性, 当温度高于70 ℃后, 天然酶完全失活, 而AMCP仍保留了80%以上的活性, 而在pH=3~9条件下AMCP依然保持90%左右的催化活性. 随后, 进一步探究了其类酶活性机理, 证实了锰、 铜之间的电子传导可加速活性位点中铜电对的循环, 从而促进活性氧的产生, 提高其类酶催化活性. 本研究为高效多酶活性纳米酶的构筑提供了参考, 也可为双金属层状硅酸盐在生物传感、 疾病诊疗及环境修复等领域的应用奠定了基础.     

Atomic engineering of single-atom nanozymes for enzyme-like catalysis

Enzyme mimics, especially nanozymes, play a crucial role in replacing natural enzymes for diverse applications related to bioanalysis, therapeutics and other enzyme-like catalysis. Nanozymes are catalytic nanomaterials with enzyme-like properties, which currently face formidable challenges with respect to their intricate structure, properties and mechanism in comparison with enzymes. The latest emergence of single-atom nanozymes (SAzymes) undoubtedly promoted the nanozyme technologies to the atomic level and provided new opportunities to break through their inherent limitations. In this perspective, we discuss key aspects of SAzymes, including the advantages of the single-site structure, and the derived synergetic enhancements of enzyme-like activity, catalytic selectivity and the mechanism, as well as the superiority in biological and catalytic applications, and then highlight challenges that SAzymes face and provide relevant guidelines from our point of view for the rational design and extensive applications of SAzymes, so that SAzyme may achieve its full potential as the next-generation nanozyme.

Single-atom nanozymes with definite active centers, high catalytic activities and enzyme-like selectivities promote the nanozyme research entering a new period of atomic level.     

When Nanozymes Meet Single-Atom Catalysis

Nanomaterials with enzyme-like activities, coined nanozymes, have been researched widely as they offer unparalleled advantages in terms of low cost, superior activity, and high stability. The complex structure and composition of nanozymes has led to extensive investigation of their catalytic sites at an atomic scale, and to an in-depth understanding of the biocatalysis occurring. Single-atom catalysts (SACs), characterized by atomically dispersed active sites, have provided opportunities for mimicking metalloprotease and for bridging the gap between natural enzymes and nanozymes. In this Minireview, we illustrate the unique properties of nanozymes and we discuss recent advances in the synthesis, characterization, and applications of SACs. Subsequently, we outline the impressive progress made in single-atom nanozymes and we discuss their applications in sensing, degradation of organic pollutants, and in therapeutic roles. Finally, we present the major challenges and opportunities remaining for a successful marriage of nanozymes and SACs.     

单原子材料在电化学生物传感中的研究进展

电化学传感器具有响应速度快、 专一性强及准确性高等特点, 已成为生物传感快速检测的重要发展方向之一, 但目前难以达到对单个生物分子的检测水平, 这主要受限于作为核心部件的探针材料. 单原子材料由于其简单明确的原子局域结构, 且具有媲美于生物酶的统一活性位点, 是一种极具潜力的探针材料, 因此受到了广泛关注. 本文综合评述了具有均一局域配位环境的单原子材料的合成, 以及其在电化学生物传感中的应用, 并对单原子材料在未来电化学生物传感中面临的挑战和机遇进行了展望.     

π-Conjugated Copper Phthalocyanine Nanoparticles as Highly Sensitive Sensor for Colorimetric Detection of Biomarkers

Though numerous nanomaterials with enzyme-like activities have been utilized as probes and sensors for detecting biological molecules, it is still challenging to construct highly sensitive detectors for biomarkers using polymeric materials. Benefiting from the π-d delocalization effect of electrons, excellent metal-chelating property, high electron transferability, and good chemical stability of π-conjugated phthalocyanine, the design of the copper phthalocyanine-based conjugated polymer nanoparticles (Cu-PcCP NPs) as a colorimetric sensor for a variety of biomarkers is reported. The Cu-PcCP NPs are synthesized through a simple microwave-assisted polymerization, and their chemical structures are thoroughly characterized. The colorimetric results of Cu-PcCP NPs demonstrate excellent peroxidase-like detecting activity and also great substrate selectivity than most of the reported Cu-based nanomaterials. The Cu-PcCP NPs can achieve a detection limit of 4.88 μM for the H₂O₂, 4.27 μM for the L-cysteine, and 21.10 μM for the glucose via a cascade catalytic system, which shows comparable detecting sensitivity as that of many earlier reported enzyme-like nanomaterials. Moreover, Cu-PcCP NPs present remarkable resistance to harsh conditions, including high temperature, low pH, and excessive salts. These highly specific π-conjugated copper-phthalocyanine nanoparticles not only overcome the current limitation of polymeric material-based sensors but also provide a new direction for designing next-generation enzyme-like nanomaterial-based colorimetric biosensors.     

金属单原子催化剂在电催化二氧化碳和水裂解的研究进展

利用电催化技术开发新型能源,是用来替代传统能源的一种新策略,化石燃料的大量使用从而导致相关的环境问题将会得到良好解决。对于这些技术的推广,设计并制备出高效稳定的电催化剂至关重要。单原子催化剂（SACs）在载体上具有原子分布的活性位点,是催化领域的新兴材料,具有美好的应用前景,现已成为电催化领域的研究热点。在此综述中,详细阐述了单原子电催化剂的一般载体、制备方法及其先进表征方法。同时系统总结了单原子电催化剂在能量转化和环境保护(CO2还原、水裂解）方面的应用。基于各种单原子催化剂研究的最新进展,我们简单阐述了催化机制。最后,讨论了单原子催化剂在电催化方向发展的挑战和前景,我们希望为单原子电催化剂的合成、设计和应用提供经验,更好的促进在电催化能量转换方面的发展。     

电催化过氧化氢还原的纳米材料作为潜在的辐射防护剂

纳米材料由于独特的物理化学性质,在生物医学领域显示出许多潜在的应用前景,诸如医学成像、药物输运和生物传感等. 这篇综述总结了对过氧化氢和氧还原表现出好的电催化活性的一些纳米材料显示了辐射防护性能. 作者讨论了这些纳米材料的辐射防护性能来源于它们的类酶活性,因为它们的催化性质表现为和活性氧的快速反应,为清除体内的自由基提供了一条有效通道. 作者也提出了纳米材料的电催化活性和作为临床转化关键的辐射防护性能之间关系的见解. 最后,作者指出了这些纳米材料作为新的辐射防护剂用于辐射防护治疗辅助成份所面临的挑战和将来的研究方向.     

Atomic-Level Regulation of Cobalt Single-Atom Nanozymes: Engineering High-Efficiency Catalase Mimics

Nanozymes aim to mimic the highly evolved active centers of natural enzymes. Despite progress in nanozyme engineering, their catalytic performance is much less favorable compared with natural enzymes. This study shows that precise control over the atomic configuration of the active centers of Co single-atom nanozymes (SAzymes) enables the rational regulation of their catalase-like performance guided by theorical calculations. The constructed Co-N₃PS SAzyme exhibits an excellent catalase-like activity and kinetics, exceeding the representative controls of Co-based SAzymes with different atomic configurations. Moreover, we developed an ordered structure-oriented coordination design strategy for rationally engineering SAzymes and established a correlation between the structure and enzyme-like performance. This work demonstrates that precise control over the active centers of SAzymes is an efficient strategy to mimic the highly evolved active sites of natural enzymes.     

Promotion effect of Au single-atom support graphene for CO oxidation

CO oxidation is a vital catalytic reaction for environmental purification, facing challenges due to the catalysts applied to oxidize CO are mainly rare and expensive noble catalysts. Since the high atomic availability, catalytic efficiency, and selectivity of single-atom catalysis, it has been widely studied and proven to be brilliant in CO oxidation. Au single-atom catalysts are regarded as excellent single-atom catalysts in oxidizing CO, whose progress is limited by the indistinct understanding of the reaction mechanism and role of the active atom. Hence, DFT calculation was used to investigate CO oxidation processes, active mechanisms, and the role of Au single-atom. Graphene involving prominent physical and chemical properties was selected as a model supporter. The single-atom support graphene materials exhibit better CO oxidation activities than pristine graphene, among which CO oxidation property on Au/GP is the highest with a 0.38 eV rate-determining barrier following ER mechanism. The outstanding performances including excellent electronic structures, adsorption properties, and strong activation of intermediate products contribute to the high CO oxidation activity of Au/GP, and the Au single-atom is the active center. Our work provides a novel guide for single-atom catalytic CO oxidation, accelerating the development of single-atom catalysis.     

Recent Advances on Nanozyme-based Electrochemical Biosensors

Nanozymes are nanomaterials with enzyme-like catalytic activities. The unique features of nanozymes (such as high stability, low cost, large surface area for bioconjugation, ease of storage, and multi-functionalities) offer unprecedented opportunities for designing electrochemical biosensors. Recent years have witnessed the rapid development of nanozyme-based electrochemical biosensors. To highlight these achievements, this review first discusses the representative nanozymes including peroxidase mimics, oxidase mimics, hydrolase mimics, and superoxide dismutase mimics used in electrochemical biosensors. Then, it summarizes the bioanalytical applications for the detection of various analytes. Finally, current challenges and future research directions are summarized.