用于赭曲霉毒素A检测的电化学适配体生物传感器的研究进展

赭曲霉毒素(Ochratoxin)是一类主要由曲霉菌和青霉菌产生的次生代谢产物,其中赭曲霉毒素A(OTA)的毒性最强。OTA相当稳定,常规的食品加工难以去除,若摄入受OTA污染的食品或药物会对人类造成严重的危害。实现对OTA的灵敏和快速检测是及早发现和处置OTA污染的关键。近年来,核酸适配体因其独特的优点,被作为抗体的替代物用于构建OTA电化学生物传感器。本文介绍了经典的OTA检测方法和基于适配体的电化学生物传感检测方法,从OTA电化学适配体传感器的适配体优化、新型材料应用以及生物信号放大技术的应用等三个方面总结了该生物传感技术的研究现状,并对其未来的发展进行了展望。     

基于铂纳米颗粒@金属有机骨架纳米模拟酶的无标记电化学赭曲霉毒素适体传感器的构建

以具有类过氧化物酶性质的Pt NPs@Mn-MOF纳米复合材料作为电极基底, 采用丝网印刷电极构建了一种无标记型电化学适体传感器, 用于赭曲霉毒素(OTA)的检测. 利用Pt NPs@Mn-MOF的模拟酶特性, 将其作为电极基底用于捕获OTA适体链, 同时催化H₂O₂还原产生电流响应信号. OTA的引入会减少纳米酶的催化活性位点, 从而导致电流信号降低. 在0.01~300 ng/mL范围内, 随着OTA浓度的增加, 电流响应值逐渐降低; 采用计时电流法检测电流响应信号, 从而间接实现了对OTA的定量检测. 此外, 该生物传感器通过U盘式小型工作站进行检测, 不仅可与电脑连接进行检测, 还可与手机连接进而实现实时检测, 并且其检测灵敏度高、 重现性好, 检出限低至3.33 pg/mL(S/N=3). 该传感器可用于真实玉米样品中OTA的检测, 在真菌毒素现场检测中展现出潜在的应用价值.     

基于电化学传感器检测赭曲霉毒素A的研究进展

赭曲霉毒素A(Ochratoxin A,OTA)是一种由赭曲霉、青霉菌等真菌产生的次级代谢产物,在自然界分布广泛,具有肝毒性、肾毒性、致癌、致突变作用.鉴于其危害的严重性和污染的广泛性,发展高灵敏度的OTA检测技术引起了研究者的广泛关注.该文阐述了近年来新型电化学传感技术在OTA检测方面的发展及应用,全面综述了目前OT...     

光学适配体传感器检测赭曲霉毒素A的研究进展

赭曲霉毒素A(Ochratoxin A,OTA)是真菌产生的次级代谢产物,性质稳定,不易去除,人体摄入后将产生严重的健康危害。数十年来,核酸适配体不断发展,成为生物传感器的重要识别元件之一,适体传感器被广泛用于生物、医药、疾病等分析检测。本文总结了用于检测OTA的经典方法和基于核酸适配体的生物传感器方法,并主要从光学适配体传感器方面阐述了近年用于检测赭曲霉毒素A的适配体传感器,并对其进行了总结和展望。     

光学适配体传感器检测赭曲霉毒素A的应用进展

赭曲霉毒素A(OTA)是由曲霉和青霉产生的一种真菌毒素,具有强烈的肝肾毒性,并有致畸、致癌的危害。OTA广泛存在于如小麦、玉米、咖啡、葡萄等谷物及食品中,严重危害人类健康。鉴于其危害的严重性和分布的广泛性,发展方便快捷、高灵敏度的OTA检测技术具有重要意义。目前检测OTA的方法有薄层色谱法、高效液相色谱法、荧光分析法及酶联免疫吸附测定法等,这些方法通常成本高、操作复杂且费时。光学适配体传感器发展迅速,在OTA检测领域表现出巨大优势,因此综述了荧光型（包括标记型和免标记型）、比色型、化学发光型以及其他类型（表面等离子体共振、侧向层析、表面增强拉曼散射型）光学适配体传感器检测OTA的原理、性能及在2011-2023年间的相关应用,并对方法面临的问题进行了总结以及未来的的发展趋势进行了展望（引用文献81篇）。     

基于核酸适体的电化学生物传感研究

核酸适体是一类经由指数富集的配体系统进化（SELEX）技术在体外筛选获得的单链寡核苷酸片段,由于具有可人工批量合成、价格低廉、易于功能化修饰、特异性强、亲和力高、免疫原性低、批间差异小、热稳定性好等优良特性,在分析化学、疾病治疗以及生物医学研究等诸多领域备受关注。结合代表性案例,该文综述了核酸适体在电化学生物传感领域的应用。首先简要概述了核酸适体及电化学适体传感器的特点,分类阐述了电化学适体传感器在小分子化合物、蛋白质、外泌体、循环肿瘤细胞（CTCs）以及病原微生物检测中的应用,并重点介绍了相关检测方法的原理、分析特性以及所应用的信号放大策略,最后对电化学适体传感器的发展进行了展望。     

基于核酸适体的电化学生物传感器*

核酸适体是一类体外筛选的、可与目标分子高效、高特异亲合的RNA或DNA寡核苷酸片段,与常规识别分子（如抗体等）相比,核酸适体作为一类新型识别分子具有明显特色和优势,已被广泛应用于生物传感等分子识别和应用研究领域。本文就基于核酸适体的电化学生物传感器（标记型和非标记型）的近期进展作简要评述,包括适体简介、标记型（“信号衰减”型、“信号增强”型、酶标记型和纳米粒子标记型）和非标记型电化学适体生物传感器等内容。     

电化学和电化学发光核酸适体传感器

核酸适体具有亲合力强、选择性高、稳定性好、易于修饰等优点,广泛用于对目标物如蛋白质、小分子等的灵敏检测.电化学具有成本低、灵敏度高、仪器小巧等优点.近年来,构建基于核酸适体的电化学传感器,已经成为一个热门的研究领域.本文重点评述了2005年以来核酸适体的电化学传感器的研究进展,并展望其发展前景.     

面向活体分析的核酸适体电化学生物传感研究

化学是生命活动的物质基础.在活体层次上精准获取生理活性分子的分布和含量的变化规律对于了解和研究生理和病理过程具有重要的意义.电化学方法,特别是基于核酸适体的电化学生物传感器,由于兼具高特异性识别、检测对象广以及易于微型化等优良特性,已成为复杂生理环境中实现快速、灵敏和高选择性检测的有效工具.本文综述了核酸适体电化学生物传感器的设计以及在活体分析中的应用,并对其未来发展趋势进行了展望.     

构建电化学适配体传感器快速检测中药材中的赭曲霉毒素A

利用壳聚糖（CS）、还原氧化石墨烯（rGO）与氮掺杂多壁碳纳米管（N-MWCNTs）合成N-MWCNTs-rGO-CS复合材料,制备修饰电极,结合赭曲霉毒素A(OTA)的特异性适配体,构建高灵敏度电化学生物传感器,并用于中药中OTA的含量测定。在最优条件下,峰电流变化值与OTA浓度对数值的线性响应范围为2.3 pmol/L～2.3 nmol/L,检测限为0.53 pmol/L。应用该方法对中药饮片中OTA的含量进行加标回收实验,回收率在97.6%～103.2%之间。该方法有望用于中药材中OTA污染的快速检测。     

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.     

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.     

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.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

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.