功能性CdTe量子点荧光增敏法测定盐酸多巴胺

以CdTe量子点作为荧光探针,基于荧光增敏法对盐酸多巴胺进行了定量检测,考察了缓冲溶液体系、量子点浓度、反应时间等多种因素的影响。实验结果表明,在pH7.5的0.2 mol/L Na2HPO4-NaH2PO4缓冲液中,反应时间为20 min,盐酸多巴胺浓度为1.2×10-8~1.0×10-7mol/L时,其线性回归方程为△F=-27.47+25.54c(10-8mol/L),相关系数和检测限分别为0.9992和6×10-11mol/L。该方法为盐酸多巴胺的测定提供了新的方法。     

水溶性量子点碲化镉测定同型半胱氨酸的研究

以巯基丙酸为稳定剂,在水溶液中一步合成了CdTe量子点,以该量子点为荧光探针,基于荧光增敏法对同型半胱氨酸(Hcy)进行选择性测定,考察了缓冲体系、缓冲液浓度、缓冲液pH值、反应时间、量子点浓度等多种因素的影响.在0.05 mol/L、pH 8.8的磷酸二氢钠-磷酸氢二钠缓冲液中,当量子点浓度为1.2 mmol/L、反应时间为10 min时,该方法的线性区间为0.1 ～60 μmol/L,检出限为8×10-8 mol/L.     

水溶性CdTe量子点荧光猝灭法测定尼群地平的研究

以巯基乙酸为稳定剂,直接合成了水溶性CdTe量子点。基于尼群地平对合成量子点的荧光猝灭效应,建立了一种简便、快速和灵敏地测定尼群地平的分析方法。考察了缓冲体系、缓冲液浓度、缓冲液pH值、反应时间、量子点浓度对尼群地平测定的影响,在0.03 mol/L、pH值为8.3的Tris-HCl缓冲液中,当量子点的浓度为6.0×10-4mol/L、反应时间为5 min,体系的相对荧光强度与尼群地平的质量浓度呈良好线性关系,其线性范围为1.09~65.4 mg/L,线性系数为0.998 6,检出限(S/N=3)为0.11 mg/L。该方法已成功用于药片中尼群地平的测定,与中国药典中的标准方法比较,结果满意。同时该文对尼群地平与CdTe量子点的反应机理进行了初步探讨。     

CdTe量子点荧光猝灭法测定奥沙利铂中微量银

以谷胱甘肽作为稳定剂,100℃恒温回流,直接合成水溶性CdTe量子点。基于Ag+对合成的CdTe量子点的荧光猝灭效应,建立了测定抗癌药物奥沙利铂中微量银的方法。考察了量子点浓度、缓冲液种类、缓冲液浓度、缓冲液pH和反应时间对银离子测定的影响。当量子点浓度为0.004 g/L时,在0.10 mmol/LpH7.4的磷酸缓冲溶液中,反应时间为5 min,体系的相对荧光强度与Ag+的质量浓度呈良好的线性关系,其线性范围为16.42～98.50μg/L,线性相关系数为0.9975,检出限为0.12μg/L。     

谷胱甘肽稳定的CdTe量子点荧光猝灭法测定痕量过氧化氢

以谷胱甘肽稳定的CdTe量子点作为荧光探针,基于荧光猝灭法对过氧化氢进行了定量检测,考察了缓冲溶液体系、量子点浓度、反应时间等多种因素的影响。实验结果表明,在pH=7.2的Na2HPO4-NaH2PO4缓冲液中,反应时间为15min,过氧化氢浓度为1.0×10-6～3.0×10-5 mol/L范围时,其线性回归方程为△F=9.78+7.56c(10-6 mol/L),线性相关系数和检测限分别为0.9992和1.27×10-8 mol/L。谷胱甘肽稳定的CdTe量子点荧光猝灭法已用于水样的测定,回收率在96%～103%之间,相对标准偏差RSD不大于3.3%,结果令人满意。     

微波辐射法制备水溶性CdTe/ZnS量子点及其与司帕沙星的作用

以巯基乙酸为稳定剂,通过微波加热在水溶液中制备了CdTe/znS量子点.研究了pH值、反应时间、反应温度和cdTe/s<'2->浓度比等合成条件对cdTe量子点荧光光谱的影响.以CdTe/ZnS量子点为探针,探讨了喹诺酮类抗生素司帕沙星与量子点的荧光猝灭作用,结果表明,在最佳实验条件下,其线性范围为0.05～3.00μg/mL,线性相关系数为0.9954,检出限为0.01μg/mL,可将CdTe/ZnS量子点荧光探针用于司帕沙星的测定.     

以CdS量子点为荧光探针测定痕量铜

以羧甲基纤维素钠（CMC）为稳定剂,在水相中制备了CdS量子点,基于Cu2+离子对量子点荧光的猝灭作用,建立了定量测定Cu2+离子的新方法。 CdS量子点对铜离子呈现出高选择性,除Co2+和Hg2+离子外,其它常见金属离子的存在对铜的测定几乎不产生干扰。 考察了不同缓冲体系及缓冲液pH值、量子点浓度、反应时间和反应温度等因素的影响,确定了Cu2+离子的最佳分析条件,即pH=5.6,磷酸氢二钠-磷酸二氢钾缓冲溶液的浓度为0.033 mol/L,量子点的浓度为2.0×10-4 mol/L。 在最佳条件下,量子点的相对荧光强度与Cu2+离子的浓度呈很好的线性关系,该方法的线性范围为5.0×10-8~2.0×10-5 mol/L,线性回归方程为：F0/F=1.015 0+100 791.6c,检出限为8.0×10-9 mol/L。 本方法简单、快速,与文献报道的其它基于量子点荧光探针Cu2+离子分析方法相比,此法对Cu2+离子呈现出更高的选择性且具有更宽的线性检测范围。 将此法用于水样和人体头发等实际样品中Cu2+离子含量的测定,结果令人满意。     

CdTe量子点荧光猝灭法测定痕量铬(Ⅲ)

以CdTe量子点作为荧光探针,基于荧光猝灭法对Cr(Ⅲ)进行了定量检测,考察了缓冲溶液、量子点浓度、反应时间等多种因素的影响.实验结果表明,在0.1mL pH 7.3的0.2 mol/L Na<,2>HPO<,4>-NaH<,2>PO<,4>缓冲液中,反应时间为20 min,Cr(Ⅲ)浓度为2.4×10<'-7>～6.0×10<'-6>mol/L范围时,其线性回归方程为F<,0>/F=1.1274+0.0640 c(10<'-7>mol/L),相关系数和检测限分别为0.9984和4.5×10<'-8>mol/L.为Cr(Ⅲ)的测定提供了新的方法.     

基于CdTe量子点荧光增强测定阿米卡星

以水相中制备的巯基乙酸修饰CdTe量子点为荧光探针,基于N-羟基丁二酰亚胺(NHS)存在,阿米卡星能使合成的量子点荧光增强作用,建立了测定阿米卡星新的分析方法。考察了缓冲体系、量子点浓度、NHS浓度、反应时间等因素的影响,在最佳实验条件下,体系的F/F0与阿米卡星的浓度呈良好的线性关系,其线性范围为2.0×10-7~2.0×10-5mol/L,相关系数为0.9971,检出限为1.9×10-7mol/L。用于实际样品的检测,RSD≤2.1%(n=5),回收率为99.98%。     

CdTe量子点荧光猝灭法测定对硝基苯胺的含量

以CdTe量子点作为荧光探针,基于荧光猝灭法对对硝基苯胺进行了定量检测,考察了缓冲溶液体系、量子点浓度、反应时间等多种因素的影响.实验结果表明,在pH7.7的0.2 mol/L Na2HPO4-NaH2PO4缓冲液中,反应时间为10 min,对硝基苯胺浓度为1.2×10-6～2.0×10-5 mol/L范围时,其线性回...     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

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.     

正丁胺对激光染料荧光谱影响的研究

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.