MXene在电化学传感器中的应用

过渡金属碳化物或氮化物(MXene)作为一种新型的二维层状材料,由于具有良好的导电性、水中分散性、高的生物相容性和稳定性等,在电化学传感领域具有巨大的应用潜力。将MXene与其他纳米材料复合,可以扬长避短,在性能上实现优势协同和功能互补,有效提高电化学传感器的灵敏度和选择性。本文按照检测物的种类进行分类,综述了基于MXene材料构建的电化学传感平台在生物标记物和环境污染物检测中的应用,并讨论了MXene材料在电化学传感领域未来研究发展和应用中所面临的挑战。     

基于新型纳米传感材料的DNA生物传感器的应用

DNA是构建纳米技术和生物传感技术新设备的良好构建体.DNA生物传感器由于具有灵敏度高、选择性好等特点,近年来获得了飞速发展.研究发现,金属纳米粒子(MNPs)、碳基纳米材料等一系列纳米材料在传感器设计中提高了电化学DNA传感器的传感性能.本文侧重介绍了场效应晶体管、石墨烯、碳纳米管等新型纳米传感材料,以及基于这些材料...     

基于电化学还原氧化石墨烯的电化学传感

石墨烯作为理想的电极材料,由于其优异的物理和化学性质,在电催化和电分析领域已得到了广泛的关注。由于石墨烯的不可逆团聚现象使其在电化学各领域的应用受到了极大的限制,而氧化石墨烯制备简单、易得,且具有良好的亲水特性,可弥补上述不足,但其结构中富含的各种含氧基团又会导致氧化石墨烯修饰界面的电子传输能力降低,不利于电催化反应和高灵敏传感器的构筑。采用适当的还原方法可减少和控制氧化石墨烯表面的含氧基团的数量,以恢复石墨烯较为完善的平面共轭结构,提高其导电性和调节带隙,达到调控材料电催化性能的目的。基于电化学还原氧化石墨烯(ERGO)得到的本征及各类无机、有机等ERGO类复合材料的电化学传感器具有明显的优势,已被广泛应用于各种电催化及电化学传感领域。本文就基于ERGO类材料的电化学传感器的近期进展作了简要评述,论述了此类电化学传感平台的特点、制备原理和方法、分类以及在各类环境污染物、食品和药物、DNA及生物等领域的电化学传感应用,并就此类电化学传感器的发展方向和应用前景进行了展望。     

光电化学传感材料的制备及应用进展

光电化学传感材料是光电化学传感器的核心功能材料,其结构性质决定了光电化学传感器的分析性能和应用范围。本文介绍了常用光电化学传感材料的制备方法及应用领域,综述了近年来该领域的研究进展并对光电化学传感材料未来的发展方向进行了展望。     

抗坏血酸电化学传感研究进展

抗坏血酸是维持人体正常功能的必需生物小分子物质,间接或直接地参与众多人体关键的生物反应过程。电化学检测抗坏血酸具有响应时间快、灵敏度高和操作简单等众多优势,是近些年传感研究的热点。本文系统介绍了安培型电化学传感器的工作原理,综述了近年来抗坏血酸电化学传感的研究进展。基于不同材料构建的抗坏血酸传感器的性能,结合各传感材料的性质,对其传感优缺点进行了分析与总结,最后对抗坏血酸电化学传感的发展方向和趋势进行了展望。     

基于MOF修饰的亚硝酸盐电化学传感器的研究进展

简单介绍了亚硝酸盐电化学传感器的基本原理和结构，详细综述了基于MOF材料修饰的亚硝酸盐电化学传感器的研究进展。其中包括原始MOF以及基于碳材料、金属纳米粒子、金属氧化物、蛋白/酶修饰的MOF复合材料等五个方向，阐述了不同类型MOF材料出色的理化性质和传感性能，以及构建亚硝酸盐电化学传感器的检测原理、检出限与实际样品应用等，最后展望并讨论了未来基于MOF材料可构建的亚硝酸盐电化学传感器的研究方向。     

可穿戴生物电化学传感器的研究与应用进展

随着物联网的发展,可穿戴生物电化学传感器受到了广泛关注。可穿戴传感器件采用液体导体、导电聚合物薄膜、水凝胶等材料作为柔性电极,集优异的机械性能与传感性能于一体,为人们的生产和生活带来了极大的便利,已被广泛用于医疗诊断、健康监测和环境监测等领域。然而,目前可穿戴生物电化学传感器在美观隐形性和生物亲和性等方面仍存在一些问题。本文从可穿戴传感器件的制备工艺及柔性材料入手,概括分析了近年来可穿戴生物电化学传感器件的研究与应用进展,对其所面临的挑战与困难进行了总结,并展望了可穿戴生物电化学器件未来的发展方向,为进一步改进可穿戴传感器件的集成方法、提高其传感性能以及实现智能化信号传输等提供了参考。     

基于共价有机框架的电化学生物传感器在生物样品检测中的应用

共价有机框架材料(Covalent Organic Frameworks, COFs)是一种具有纳米级结构有序性的二维或三维有机结晶材料, 具有高度周期性和可修饰性等结构优点. 基于COFs制备的电化学生物传感器具有灵敏度高、特异性强、重复性好等特点, 在检测生物样品方面具有广阔前景. 本综述简要概述了COFs的合成方法与策略、电化学生物传感器的介绍与分类以及COFs在电化学生物传感检测生物样品领域的应用. 最后本综述对COFs材料在生物传感领域的技术瓶颈与未来的发展方向进行了总结与讨论.     

DNA步行者在检测传感中的应用

DNA步行者（DNA Walker）是一种基于化学能布朗运动的人工模拟机器,由构象迁移和链置换反应驱动,在纳米轨道上实现物质的检测运输。基于DNA Walker的生物传感器是一种集生物和纳米技术于一体的新型高效传感器,在食品安全检测、生物传感等领域有巨大的应用潜力。本文介绍了DNA Walker的发展现状,并通过讨论,系统概述了DNA Walker传感器的设计原理及其在检测传感中的应用。总结了DNA Walker传感器的性能优势和所面临的挑战,并对该技术的研究前景进行了展望。     

石墨烯纳米复合材料在电化学生物传感器中的应用

将石墨烯与其他纳米材料复合,是一种拓展或增强其应用的有效方法。借助不同组分间的协同作用,可以改善石墨烯的电学、化学和电化学性质,拓展和增强石墨烯的电化学效应,为固定氧化还原酶,实现直接电化学提供新型、高效的平台,应用于第三代电化学生物传感器的设计和制备,对葡萄糖、胆固醇、血红蛋白、DNA、H₂O₂、O₂、小生物分子等的检测显示出了优异的灵敏度和选择性。本文综述了基于石墨烯构筑的纳米复合材料在电化学生物传感器中的应用研究,包括石墨烯与贵金属、金属氧化物/半导体纳米粒子、高分子、染料分子、离子液体、生物分子等的纳米复合材料,并对石墨烯材料在电化学领域的发展方向和应用前景进行了展望。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.