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1.
水溶性发光金量子点灵敏检测L-半胱氨酸 总被引:1,自引:1,他引:0
室温下一步合成了一种蓝色发光金量子点。 该金量子点具有良好的水溶性和生物相容性,金量子点平均粒径为3.0 nm,在波长305 nm光激发下,发射430 nm蓝色荧光。 实验发现,一定量L-半胱氨酸对金量子点430 nm处荧光发射有显著的增强作用,由此可建立一种简单、迅速、灵敏检测L-半胱氨酸的新方法。在最佳条件下,金量子点荧光强度与L-半胱氨酸在0~4.0 μmol/L浓度范围内呈线性关系,线性相关系数R2=0.9976,对2.0 μmol/L L-半胱氨酸的11次测定结果的相对标准偏差(RSD)为2.8%,以3倍标准偏差计算本法对L-半胱氨酸测定的检出限为5 nmol/L。 相似文献
2.
迷迭香酸的CdTe量子点荧光探针同步荧光法测定 总被引:1,自引:0,他引:1
基于迷迭香酸对CdTe量子点荧光的猝灭效应,建立了一种高灵敏度的测定微量迷迭香酸的同步荧光法.在pH 5.7的缓冲溶液中,当固定波长差为210 nm时,CdTe量子点的同步荧光最大发射波长位于320 nm.在最佳实验条件下,迷迭香酸质量浓度在0.36 ~11.52 mg·L-1(1.00×10-6 ~3.20×10-5 mol/L)范围与CdTe量子点的同步荧光强度存在良好的线性关系.其线性回归方程为I0F/IF=0.931 7+0.128 9 ρ(mg·L-1),相关系数r=0.998 2,检出限为0.16 mg·L-1.10次重复测定2.16 mg·L-1 的迷迭香酸,相对标准偏差为2.8%.同时对其同步荧光猝灭机理进行了探讨. 相似文献
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以硒化铜纳米颗粒为能量受体,以罗丹明B为能量供体,二者之间通过光诱导电子转移而猝灭罗丹明B的荧光;而 L-半胱氨酸能够诱导罗丹明 B 荧光的恢复,从而建立了测定 L-半胱氨酸的新方法。在pH 4.6、温度为30℃条件下混合2 mun后,罗丹明B在575 nm处的荧光强度与溶液中L-半胱氨酸的浓度在2.5×10-7~1.1×10-6 mol/L浓度范围内呈良好的线性关系,检出限(3σ/k)为5.5×10-8 mol/L。常见的氨基酸对半胱氨酸的测定干扰小,方法快速、选择性好。 相似文献
4.
用L-半胱氨酸(L-cysteine)作为稳定剂,以制备的CdTe量子点为核模板,水相合成了具有近红外发光的Ⅱ型核壳CdTe/CdSe半导体量子点。实验考察了合成温度,核模板的尺寸和组分比等因素对合成高质量的CdTe/CdSe量子点的影响。用紫外-可见吸收和荧光光谱研究了合成的量子点的光学性质。在优化的合成条件下,荧光发射光谱在586~753nm范围连续可调,荧光量子产率高达68%;通过X-射线衍射(XRD),X射线光电子能谱(XPS)和透射电镜(TEM)对合成的Ⅱ型核壳CdTe/CdSe量子点进行了结构和形貌表征。 相似文献
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采用一锅法,通过控制镉硫比合成了表面富镉离子的硫化镉量子点,利用L-半胱氨酸可与量子点表面Cd2+结合,使量子点表面钝化,从而增强其电化学发光信号的性质,实现了对L-半胱氨酸的选择性检测.对合成的量子点进行了表征,优化了检测条件.在优化的条件下,L-半胱氨酸在5.0×10-9~1.0×10-5 mol/L浓度范围内与ECL信号呈良好的线性关系,检出限为1.2×10-9 mol/L(S/N=3).本方法对L-半胱氨酸具有良好的选择性,用于实际样品中L-半胱氨酸的测定,结果令人满意. 相似文献
7.
CdTe/CdS量子点-蛋白质与头孢曲松钠的相互作用 总被引:4,自引:2,他引:2
以3-巯基丙酸为稳定剂,采用水热法合成了具有优异光学性质的CdTe/CdS核壳型量子点,量子产率为13.8%。量子点与牛血清白蛋白(BSA)偶联后荧光强度明显增大。通过测定荧光强度确定了偶联的最佳反应条件:pH7.4,反应温度37℃,反应时间40min。研究了溶液pH值和NaCl浓度对量子点及量子点-BSA溶液荧光强度的影响。对牛血清白蛋白测定的线性范围为1.1~19.5mg/L;检出限为0.47mg/L。头孢曲松钠对量子点-BSA的荧光有明显猝灭作用,荧光猝灭程度与其浓度有良好的线性关系。实验结果表明为静态猝灭,头孢曲松钠与BSA按1∶1结合,结合常数为6.31×103L/mol。用圆二色光谱技术探讨了其对BSA构象的影响。 相似文献
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以硫脲为硫源,采用谷胱甘肽(GSH)和柠檬酸钠(SC)为配体,通过水热法制备了水溶性AgInS2/ZnS(AIS/ZnS)核/壳结构量子点。系统研究了反应温度和配体用量对量子点的合成及其荧光性能的影响。采用X射线衍射(XRD)、透射电子显微镜(TEM)、紫外可见吸收光谱(UV-Vis)和光致发光光谱(PL)分别对量子点的物相、形貌和光学性能进行了表征,并考察了量子点的稳定性。实验结果表明,随着反应温度从70℃升高至90℃,促进了ZnS壳层的形成,有效地钝化了量子点的表面缺陷,获得的AIS/ZnS核/壳量子点的发光强度显著提高,发光峰位从600 nm蓝移至580 nm。配体的添加可以有效地平衡Zn^2+的化学反应活性,减缓ZnS壳层的生长,抑制核壳界面缺陷的形成,还能消除量子点的表面态,当nGSH/nZn^2+=2.0,nSC/nZn^2+=2.5时,AIS/ZnS量子点的荧光性能最佳。此外,AIS/ZnS核/壳结构量子点还具有优异的光学稳定性。 相似文献
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以L-半胱氨酸为碳源、硫源及氮源,一步水热法制得水溶性好、稳定性高的硫氮共掺杂碳量子点SN-CDs。基于Pb~(2+)对其荧光的淬灭作用,构建了高选择性与高敏感度的荧光探针,可应用于Pb~(2+)的快速检测。运用透射电镜、紫外-可见吸收光谱、Fourier红外光谱和荧光光谱表征了SN-CDs的结构及光学性能。结果表明,Pb~(2+)浓度在2~50μmol/L范围内,与SN-CDs的荧光淬灭率之间呈良好的线性关系,相关系数为0.9992,检出限为0.2μmol/L。方法用于自来水中Pb~(2+)的测定,回收率为94.7%~100.7%。 相似文献
11.
E Kissa 《Journal of chromatography. A》1985,319(3):407-411
12.
Han F Zhu X Mu G Zeng B Cheng P Shen B Wen HH 《Journal of the American Chemical Society》2011,133(6):1751-1753
We successfully synthesized the copper-based pnictide LiCu(2)P(2), which was reported as a superconductor with T(c) = 3.7 K before. The temperature dependence of resistivity and DC magnetization was measured on both polycrystalline and single-crystalline LiCu(2)P(2). However, our repeatable synthesizing and measurements showed no superconducting transition either in resistivity or DC magnetization above 2 K. A metallic behavior can be seen in resistivity, and a Curie-Weiss behavior was observed in DC magnetization from 2 to 300 K. We have also carried out the Hall effect and MR measurements on the sample, from which we conclude that the LiCu(2)P(2) has a single-band character. We also synthesized the polycrystalline Li(1-x)Cu(2)P(2), LiCu(2-x)P(2), and Li(1+x)Cu(2-x)P(2) with different stoichiometries, and observed no superconductivity in all the samples. 相似文献
13.
M. M. El-Dessouky I. Gar Al-Alm Rashed 《Journal of Radioanalytical and Nuclear Chemistry》1988,120(2):361-368
2-hexanoyl-5-(2-hydroxy 2-propyl)furan (HHPF), has been investigated as the principal product of radiolysis of 2-hexanoyl-furan (HF) in 2-propanol. The effect of absorbed dose on the product yields has been examined. Possible mechanisms for the formation of radiolytic products are discussed. 相似文献
14.
Alan L. Balch Catherine H. Lindsay Marilyn M. Olmstead 《Journal of organometallic chemistry》1979,177(2):C22-C26
Dimethylacetylene dicarboxylate and hexafluoro-2-butyne add to Pd2(dpm)2Cl2 (dpm = Ph2PCH2PPh2) to give crystalline adducts Pd2(dp)2(μ-acetylene)Cl2. An X-ray crystal structure of Pd2(dpm)2(μ-C4F6)Cl2 reveals that the acetylene has inserted into the metalmetal bond and has been transformed into a cis-dimetallated olefin. The central CC bond length of the bridging olefin is 1.338(16) Å. The coordination about each of the two similar palladium ions is planar and involves two trans-phosphines (one from each of the bridging dpm ligands), a terminal chloride, and one carbon of the bridging olefin. Both Pd2(dpm)2Cl2 and Pd2(dpm)2(μ-C2{CO2H3}2)Cl2 catalyze the cyclotrimerization of dimethyl-acetylene dicarboxylate. 相似文献
15.
Stéphanie Ricol Etienne Vernaz Philippe Barboux 《Journal of Sol-Gel Science and Technology》1997,8(1-3):229-233
Gels have been synthesized in the SiO2-Na2O-ZrO2 system and calcined at various temperatures up to 700°C. They have been studied by infrared absorption spectroscopy. The position of the asymmetric stretching frequency of the SiO4 unit is used as a tracer of the homogeneity. It is shown that sodium increases the solubility of zirconium in the silica matrix as already observed in fused glasses. 相似文献
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纳米ZrO2在O2/H2气中的表面效应 总被引:1,自引:0,他引:1
用ESR方法研究了一种纳米ZrO2在普通H2气中升温条件下的表面效应.ZrO2上Zr3+的中心量约为1×10-7mol/g.这些Zr3+中心是ZrO2表面一些O2-配位不饱和的Zr原子点位.在普通H2气中,ZrO2上的Zr3+中心数在温度低于400℃时变化很小.但在这一温度范围内从室温升温时,由ZrO2表面羟基的H2还原引起的F中心量随温度的升高而增加.温度高于400℃时,ZrO2表面的Zr3+及F中心可与普通H2气中存在的少量O2气作用产生O2-,并伴随ZrO2表面羟基的脱除而形成新的Zr3+. 相似文献
18.
M. M. El-Dessouky F. Abdel-Rehim A. -A. Abdel-Azim I. Gar-Alm Rashed 《Journal of Radioanalytical and Nuclear Chemistry》1988,125(2):485-492
Gamma radiolysis of 2-acetylfuran (AF) in 2-propanol, in absence of atmospheric oxygen, has been investigated. The radiation yields of hydrogen, methane at different doses as well as radiolytic products in solution were determined. The radiolytic products were determined by gas chromatography coupled with mass spectrometry. The mechanisms for formation of detected radiolytic products and the effect of (AF) concentration on hydrogen and methane yields are discussed. 相似文献
19.
I. Ya. Zaitseva I. S. Kovaleva V. A. Fedorov 《Russian Journal of Inorganic Chemistry》2014,59(11):1340-1342
The interaction in the HgBr2-CdBr2-PbBr2 ternary system was studied by differential thermal analysis; the isoconcentration section of the system at 50 mol % CdBr2 was investigated. Based on the results of the study, a projection of the liquidus surface of the HgBr2-CdBr2-PbBr2 ternary system to the composition triangle was constructed; the boundaries of the primary crystallization fields were determined for three phases: HgBr2 (degenerate field), solid solution α based on CdBr2, and solid solution β based on PbBr2; and isotherms were drawn. A ternary eutectic has the composition 93 mol % HgBr2-1 mol % CdBr2-6 mol % PbBr2 and melts at 235°C. 相似文献
20.
V. K. Gamov V. A. Kaminskii M. N. Tilichenko 《Chemistry of Heterocyclic Compounds》1972,8(10):1253-1256
The reaction of 2,2'-methylenedicyclohexanone with HCN and hydrazine in aqueous alcohol was studied at various pH values. Conclusions were drawn regarding the spatial configurations of the reaction products.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1387–1390, October, 1972. 相似文献