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1.
利用纳米颗粒对目标DNA的富集、分离作用以及阳离子荧光共轭聚合物良好的荧光特性,建立了一种特异性检测DNA的新方法.首先将标记有猝灭基团的DNA捕获探针修饰到纳米颗粒上,捕获互补的DNA分子;然后加入S1核酸酶,除去未捕获到互补DNA的捕获探针;最后用Dnase Ⅰ将颗粒上的双链切断,使猝灭基团从纳米颗粒上解离下来,与阳离子荧光共轭聚合物结合并猝灭其荧光.结果表明,目标核酸的浓度与该聚合物的荧光猝灭程度正相关,且具有良好的特异性,线性响应范围为5.0~40 nmol/L; 检出限为3.7 nmol/L(S/N=3). 相似文献
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研究了8个含羟基取代基的Schiff碱捕获自由基——ABTS .和DPPH——的性能。结果发现,Schiff碱捕获自由基的性能首先与分子中所含有的羟基的个数有关,随着羟基数目的增多,Schiff碱捕获自由基的能力增强。大的共轭体系以及羟基处于N原子邻位可增强该Schiff碱捕获ABTS .的性能;但对于捕获DPPH来说,只有同时将大的共轭体系与处于N原子邻位的羟基结合在同一分子中,才能表现出较强的捕获DPPH的性能。由此可见,DPPH对于检测Schiff碱中羟基捕获自由基的性能是一种更为专一的试剂。 相似文献
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本工作设计研制了一套激光捕获与原位稳态及时间分辨荧光光谱检测系统,该系统将激光捕获技术与稳态及时间分辨荧光光谱检测技术相结合,实现了对亚微米级微粒的原位稳态及时间分辨发光性质研究.利用研制的仪器研究了荧光标记聚苯乙烯微球的激光捕获过程、以及捕获微粒的原位稳态及时间分辨荧光光谱.本工作为单个纳米粒子发光性质的研究开辟了一条新的途径. 相似文献
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《高等学校化学学报》2018,(12)
基于八元瓜环(Q[8])可使吖啶橙(AD)的荧光降低的性质制备了荧光探针2AO@Q[8],当在该探针中加入多菌灵后荧光强度又逐渐增强,利用此超分子配合物的荧光效应,构建了一种能够检测多菌灵的超分子荧光探针.研究结果表明,该探针在水溶液中对多菌灵具有良好的选择性,在一定浓度范围内其线性关系良好,检出限为8. 14×10~(-8)mol/L.细胞成像结果显示,该探针在前列腺癌细胞中对多菌灵具有良好的响应,可用于生物细胞内多菌灵的识别检测. 相似文献
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利用一种罗丹明衍生物荧光探针的开环效应检测Hg2+.在pH 7.0的Tris-HCl缓冲液中,Hg2+与荧光探针结合导致罗丹明类衍生物开环,溶液颜色由无色变成粉红色,并且发射强的荧光.荧光强度与Hg2+浓度在20~200 ng/L范围内呈良好的线性关系,检出限为4 ng/mL.实验考察了荧光探针的选择性以及温度、pH、荧光试剂浓度和盐度对Hg2+检测的影响.结果表明该方法具有反应试剂水溶性好、选择性好和可常温检测等优点.方法应用于自来水、河水和湖水等水体中Hg2+的检测,获得较好的回收率. 相似文献
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石墨烯量子点荧光探针对碱性磷酸酶活性的高效检测 总被引:1,自引:0,他引:1
基于苯醌类物质静态猝灭石墨烯量子点(GQDs)荧光的特性, 构建了一种利用GQDs荧光探针实时、 高效检测碱性磷酸酶(ALP)活性的新方法. 过氧化氢在辣根过氧化物酶催化作用下产生羟基自由基并将邻苯二酚氧化成邻苯醌, 导致GQDs的荧光猝灭. ALP催化抗坏血酸-2-磷酸反应生成抗坏血酸, 具有较强还原性的抗坏血酸能清除溶液中的过氧化氢和羟基自由基, 抑制邻苯醌的产生, 使GQDs的荧光猝灭效果减弱. 随着ALP活性的增大, GQDs在440 nm处的荧光强度不断增强, 由此建立了一种高效检测ALP活性的新方法. 在最佳实验条件下, 该GQDs荧光探针对ALP活性的检出限为0.084 U/L. 将此方法成功用于人血清中ALP活性的检测, 为与ALP相关疾病的诊断与治疗提供了理论基础. 相似文献
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《有机化学》2020,(8)
高半胱氨酸(Hcy)被认为是血管和肾脏疾病的危险因素.因此,开发Hcy特异性荧光探针,特别是比率荧光探针具有重要的意义.基于邻羟基醛基化的苯并噻唑,合成了一种用于Hcy高选择性检测的比率荧光探针3-(苯并噻唑-2-基)-2-羟基-5-甲基苯甲醛(BA).相对于其他测试物种(包括半胱氨酸和谷胱甘肽),该探针BA对Hcy表现性出良好的选择性.探针BA自身显示出绿色荧光(544 nm),将Hcy加入到探针溶液中后,反应体系表现出蓝色荧光(478 nm).在0~1.0mmol/L浓度范围内,荧光发射强度比值(I_(478nm)/I_(544nm))与Hcy呈现良好的线性关系,检测限为1.6mmol/L.该探针BA毒性低,渗透性好,能够用于细胞中的Hcy比率荧光成像,显示其在生物体系中潜在的应用.另外,通过核磁、质谱实验和密度泛函理论计算验证了探针对Hcy的识别机理. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
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. 相似文献
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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. 相似文献
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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%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
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. 相似文献
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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. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described. 相似文献
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用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在. 相似文献
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An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction. 相似文献
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The Diels-Alder reactivity of 1,2-heteroborines (H4C4B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed. 相似文献