基于共价有机框架材料的电化学传感器研究进展

共价有机框架（COFs）材料是一类由轻质元素（C, O, N, B等）通过强共价键连接而成的新兴结晶多孔材料。COFs因其可调孔径、永久孔隙率、拓扑可设计性等优点,被广泛用于电化学传感领域。金属纳米粒子、碳材料、金属有机框架、酶等功能材料与COFs复合,可以显著提高电化学传感器的分析性能,实现高灵敏度和选择性检测。本综述阐述了基于COFs的电化学传感器的最新研究进展,总结了制备方法,并对其传感机制进行了解释。介绍了新型COFs材料的设计和合成,以及基于新型检测模式的COFs电化学传感器的研究进展。     

共价有机框架在传感中的研究进展

共价有机框架(Covalent Organic Frameworks, COFs)作为一种由有机结构单元通过共价键连接而成的晶态有机多孔材料,具有结晶性好、密度低、比表面积高以及结构可设计性强等特点,已在分子吸附与分离、催化、光电及能源等领域展现出巨大的应用潜力.近年来,COFs因其固有的结构特点,在传感领域也逐渐引起了科研工作者的广泛关注.主要综述了COFs在爆炸物传感、湿度传感、金属离子传感、pH传感、生物传感、气体传感等领域中的研究进展,并对其发展前景进行了展望.     

生物传感器在新冠病毒检测中的应用

自新型冠状病毒肺炎(COVID-19)爆发以来,准确高效、快速便捷的新型冠状病毒(SARS-CoV-2)筛查越来越在疫情防控中体现出其重要性.传统的检测方法无法满足短时间内SARS-CoV-2大规模感染时的检测需求.生物传感技术具有灵敏度高、选择性好、低成本、易于微型化等优点,其检测时间短的优势还可用于开发即时检测设备,是临床诊断中实时检测SARS-CoV-2的潜在替代方案.本综述简要阐述了光学生物传感器、电化学生物传感器、可穿戴式生物传感器、磁性生物传感器、金纳米颗粒生物传感器以及适配体生物传感器的构建方法、工作原理,并总结了其在新冠病毒检测领域的最新应用.最后本综述对生物传感器在新冠病毒检测领域的技术瓶颈与未来的发展趋势进行了总结与讨论.     

基于共价有机框架材料的纳米体系在生物医学中的应用

共价有机框架(Covalent organic frameworks, COFs)材料是通过动态共价化学法合成的一种高度有序的多孔晶态有机聚合物。COFs材料具有密度低、比表面积大、孔隙度可调、合成路线简单多样、功能单元和结构可设计、表面及孔道易功能化、物理化学稳定性高等主要特征,在分子吸附与分离、储能、光电、传感、催化、色谱材料、水处理材料和生物医学等方面受到了广泛关注。本文重点综述近年来基于COFs材料的体系在生物检测和成像、药物输送、光学治疗和联合治疗等生物医学领域的研究进展,并总结了目前COFs材料在生物医学领域所面临的挑战和未来的发展机遇。     

基于层状双金属氢氧化物的电化学生物传感器研究进展

层状双金属氢氧化物（LDHs）具有开放的二维平面结构和良好的生物相容性,是非常适合于将生物酶固定在电极表面用于生物传感器的主体材料。本文介绍了酶在LDHs材料上的固定方法,综述了近年来基于这类二维层状材料的各种电化学生物传感器的研究进展,讨论了不同类型生物传感器的设计原理和电子传递机理,并对LDHs在电化学生物传感领域...     

电化学发光免疫传感技术在生物药物分析中的研究进展

随着生物及药物分析领域的不断扩展,发展高灵敏度及高选择性的分析手段以解决复杂样品体系中低浓度待测物的分析测试问题是十分迫切的需求.电化学发光分析方法由于具有线性范围宽,灵敏度高及可控性强等优点,是处理低浓度样品的有效工具.这种方法与免疫传感技术相结合,有利于实现生物体液等复杂样品中极低含量生化物质与药物的高选择性、高灵敏度检测.本文综述了电化学发光免疫传感技术的发展状况,介绍了近年来在电化学发光免疫传感中出现的新型固相载体、电化学发光探针和共反应物、以及多组分免疫传感技术等,并对其在生物药物分析中的应用情况进行了总结.     

纳米电化学生物传感器

纳米电化学生物传感器是将纳米材料作为一种新型的生物传感介质,与特异性分子识别物质如酶、抗原/抗体、DNA等相结合,并以电化学信号为检测信号的分析器件。本文简要介绍了生物传感器的分类和纳米材料在电化学生物传感器中的应用及其优势,综述了近年来各类纳米电化学生物传感器在生物检测方面的研究进展,包括纳米颗粒生物传感器,纳米管、纳米棒、纳米纤维与纳米线生物传感器,以及纳米片与纳米阵列生物传感器等。     

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.     

基于石墨烯功能复合材料的DNA电化学生物传感器

石墨烯(Gr)是一类由单层碳原子组成的二维碳质材料,利用它独特的结构和良好的物理、化学性能,可构筑出在电催化、电化学传感器和生物传感器等领域有着巨大应用潜力的新型Gr功能复合材料。基于Gr功能复合材料的DNA电化学传感器与常规DNA传感器相比,具有明显的特色和优势,已被应用于特异DNA靶序列的识别和传感领域。本文就基于Gr功能复合材料的DNA电化学传感器的近期进展作简要评述,包括Gr与Gr基金属、金属氧化物、高分子、生物分子复合材料的电化学性能及其在DNA电化学传感中的应用,并对该类DNA电化学传感器的发展方向和应用前景进行了展望。     

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。     

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.     

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.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

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%).