基于碳纳米材料的非酶葡萄糖传感器

简述了非酶葡萄糖传感器的研究现状以及碳纳米新材料的电化学优势,主要讨论了碳纳米管、石墨烯及石墨烯氧化物、有序介孔碳、碳纤维和富勒烯等碳纳米材料与各种金属氧化物组成的复合材料构建的非酶葡萄糖传感器的电化学性能,重点探索了材料的制备方法和结构形貌对葡萄糖检测性能的影响。本文为基于碳纳米材料的非酶葡萄糖传感器的构建提供了材料选择、制备方法以及结构形貌等方面的参考,并对非酶葡萄糖传感器的发展及研究方向作出了展望。     

基于铜基金属有机框架的液栅型石墨烯晶体管高灵敏检测葡萄糖

将金属有机框架(Metal-organic frameworks, MOFs)材料的电催化活性和液栅型石墨烯晶体管(Solution-gated graphene transistor, SGGT)的信号放大作用结合,构建了一种新型SGGT无酶葡萄糖传感器。以均苯三甲酸(BTC)为有机配体,采用溶剂热法合成铜基MOF材料(Cu-BTC),利用Nafion膜将Cu-BTC材料固定到玻碳电极上,并作为栅极,以单层石墨烯作为晶体管沟道。此传感器的传感机理是基于葡萄糖在修饰有Cu-BTC的栅电极上发生电化学反应,引起施加于SGGT的有效栅电压的变化,从而改变了沟道载流子浓度和沟道电流。由于Cu-BTC对葡萄糖良好的电催化活性及SGGT的高灵敏度,Cu-BTC修饰的SGGT传感器对葡萄糖表现出优异的传感性能,线性范围为1 nmol/L～40 mmol/L,检出限低至1 nmol/L,优于大多数传统葡萄糖检测方法。同时,此传感器对汗液和血液中的主要成分(如尿素、乳酸、多巴胺、抗坏血酸、尿酸等)表现出较好的抗干扰性能,在长期重复实验中表现出良好的稳定性,并成功应用于人体汗液中葡萄糖的检测。Cu-BT...     

非酶葡萄糖传感器电极材料构建策略

电化学传感器因具有灵敏度高、检测限低等优点而得到广泛应用,将非酶电化学传感器应用于葡萄糖浓度的检测具备重要的研究价值。以金属有机骨架、碳材料和导电聚合物为基底与金属及其衍生物复合,构建的纳米复合材料修饰电极对于葡萄糖的检测具有极高的灵敏度、较低的检测限和快速响应的能力,可应用于实际样品的检测。本文综述了近年来非酶葡萄糖电化学传感器的研究进展,通过对纳米复合材料的性能比较,为非酶葡萄糖传感器的构建提供思路。     

电流型葡萄糖传感器阴极的研究

本文研究了石墨、银、钛基RuO2 /TiO2 涂层材料等几种导电材料取代铂作为葡萄糖传感器阴极的可能性 .结果表明 ,钛基RuO2 /TiO2 涂层电极的化学性质稳定 ,对析氢反应有一定的催化作用 .由石墨_环氧胶粘剂混合物—钛基RuO2 /TiO2 组成的电化学体系可以在 0 .6～ 0 .8V电压范围内检测H2 O2 的稳态氧化电流 ;在 0 .7V电压下 ,以钛基RuO2 /TiO2 涂层材料作为阴极的葡萄糖传感器的性能与以铂片为阴极的传感器性能接近 ,钛基RuO2 /TiO2 涂层材料是取代铂的最佳阴极材料 .     

电化学葡萄糖传感器

作为电化学生物传感器中最重要的研究内容之一,葡萄糖生物传感器在数十年的发展中取得了巨大进展。本文综述了近年来利用纳米技术设计的新型电化学葡萄糖传感器的主要研究进展,并从纳米材料维度分类进行了讨论。其中,零维纳米材料主要讨论了包括金纳米颗粒、银纳米颗粒以及铜、铂等金属纳米颗粒材料; 一维纳米材料主要讨论了通过模板法制备的金属或金属氧化物纳米线以及单臂或者多壁纳米管材料; 二维纳米材料主要总结了以碳为基础的石墨烯材料和一些片状的金属材料。纳米材料对电化学葡萄糖传感器的影响主要集中在生物相容性、增强检测灵敏度、酶的固定等方面。此外,本文也对电化学葡萄糖传感器的今后发展做了展望。     

纳米铂修饰电极用于提高葡萄糖传感器性能的研究

纳米材料领域的快速发展,促进了无酶葡萄糖电化学传感器的研制热潮的兴起。本论文采用计时电流沉积的方式制备了铂纳米花修饰电极,用于改善葡萄糖电化学传感器的性能,同时考察了沉积电位,沉积时间以及电解液的种类对修饰电极性能的影响。研究结果表明,在以氯铂酸(3.0mmol·L~(-1))和硫酸(0.5mol·L~(-1))为电解液,-0.2V的沉积电位,沉积900s时,可以得到葡萄糖氧化峰明显,电化学性能较好的纳米铂修饰电极,所构建的葡萄糖传感器具有较好的稳定性和重现性。     

无酶葡萄糖电化学传感器的研究进展

随着各种新型材料的层出不穷及其在葡萄糖电化学传感器方面应用的发展,无酶葡萄糖电化学传感器的研制成为葡萄糖电化学传感器的另一个研究热点.本文综述了近年来无酶葡萄糖电化学传感器的研究进展,重点介绍了电流型无酶葡萄糖传感器所使用的各种电极材料,总结了最近五年各种新型结构材料在该类传感器研制方面的应用,并对无酶葡萄糖电化学传感器发展方向和趋势进行了展望.     

基于温度的酶注射式葡萄糖生物传感器检测方法研究

针对酶注射式葡萄糖生物传感器在实际使用中因为标定液与被测液的温度不同而引起的测量结果不准确问题,提出一种基于温度的葡萄糖浓度检测方法.首先根据酶促反应动力学建立目前酶注射式葡萄糖生物传感器浓度检测模型,之后利用阿伦尼乌斯公式建立温度与浓度检测动力学模型中未知参数之间的关系,并将此关系代入浓度检测动力学模型中,以建立基于温度的浓度检测新模型.此模型以温度与酶促反应的电流初始斜率为输入值,以被测葡萄糖浓度为输出值,利用此模型提出了以反应混合液的温度和反应初始电流斜率推导被测液浓度的检测方法.利用改进的检测方法进行检测,不仅能够降低温差的影响,提高检测的准确性,还可以省略常规检测中的人工标定,避免人工标定所需的取样探头拆卸步骤,更加有利于在线使用.分别在25.0,30.0和42.0℃下检测1.5 mg/mL和2.5 mg/mL葡萄糖溶液,利用原检测方法与基于温度的检测方法进行检测,结果表明,基于温度的检测方法回收率均在95.0％以上,明显优于原检测方法.     

发酵过程葡萄糖在线检测系统的研制

发酵工艺中的高温蒸气灭菌过程使得传统"酶膜"方式葡萄糖生物传感器不能在线使用,导致不能实时控制葡萄糖的补加量,进而影响发酵的质量和产率。为了解决这一问题,本研究构建了一套用于发酵过程的葡萄糖在线检测系统。利用研制的耐高温的"酶液"方式葡萄糖生物传感器解决了"酶膜"方式传感器高温后无法正常工作的问题;利用研制的耐高温的透析取样系统解决了在线取样难题。实验表明:本传感器对葡萄糖的灵敏度达到0.259 nA/(mg/L);检出限为0.7 mg/L。对于500 mg/L葡萄糖浓度测量结果的相对标准偏差为2.02%;在0～1000 mg/L范围内,系统响应信号与葡萄糖浓度呈线性关系;本系统与商品化SBA-40E生物传感分析仪离线测量结果相比,呈现显著的线性相关关系。且线性相关方程的斜率k≈1。利用此检测系统对大肠杆菌发酵过程中的葡萄糖浓度进行了在线测量,并与SBA-40E生物传感分析仪离线测量结果进行了对比,变化趋势基本一致。     

基于多层叉指超微带电极阵列的葡萄糖传感器

采用多层工艺和光刻方法在玻璃衬底上加工了亚微米级金叉指型超微带电极阵列（IDA）,IDA电极的宽度为362nm,电极表面位于沟槽内。实验表明,所加工的IDA电极可作为生物和化学传感器的一次性超微基体电极。采用电聚合的方法将葡萄糖氧化酶（GOD）和吡咯（PPy）固定于IDA电极,该修饰电极可作为葡萄糖传感器。采用该葡萄糖传感器对磷酸钾缓冲溶液（pH7．0）中的葡萄糖浓度进行了比对测量,在2．0-7．0mmol／L的浓度范围内,传感器的响应时间为10s;灵敏度为14．6nA／（mmol／L）,相关系数为0．999。     

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.