共查询到20条相似文献,搜索用时 15 毫秒
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与传统量子点相比,碳量子点作为一种新型的荧光碳纳米材料,由于其良好的生物相容性、易于表面功能化、低毒性等优点受到了广泛关注。采用柠檬酸为碳源,氨水为氮源,热解法制备出水溶性好的氮掺杂碳量子点(NCDs)。透射电镜(TEM)观察NCDs的粒径在3nm左右;X射线光电子能谱(XPS)和傅里叶红外光谱(FIIR)证明NCDs的表面被羧基、氨基、羟基、羰基等官能团功能化,说明NCDs有很好的水溶性。研究还发现Hg~(2+)对NCDs的荧光有良好的猝灭作用,可作为荧光探针检测水中Hg~(2+)含量。在PBS缓冲液中(0.1mol·L~(-1) pH 7.0),NCDs的荧光猝灭率(F/F0)与汞离子浓度在0.001~0.1μmol·L~(-1)之间存在良好的线性关系,检出限为2.1nmol·L~(-1)。该方法灵敏度高、选择性好、方法简便,可应用于Hg~(2+)快速、灵敏的检测。 相似文献
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胶体水相法制备高量子产率及高稳定性的水溶性ZnSe量子点 总被引:1,自引:0,他引:1
采用简便的胶体水相法制备了高荧光强度且稳定性良好的ZnSe量子点(ZnSe QDs),克服了以往水相合成法稳定性差、量子产率低等缺陷。优化后的最佳合成条件为:以还原型L-谷胱甘肽作为稳定剂,L-谷胱甘肽∶Se2-∶Zn2+摩尔比为5∶1∶5,介质pH 10.5,反应温度在90~100 ℃之间。且合成后不需要采取任何光照后处理,ZnSe QDs的量子产率(QYs) 即可高达50.1%,放置3个月后荧光强度基本不变,水溶性优良。用紫外-可见分光光度法(UV-Vis)、荧光分光光度法(FL)、透射电子显微镜(TEM)等分析检测手段,对得到的ZnSe QDs的性能进行表征。合成的量子点在300 nm激发下发蓝紫色荧光(370 nm),其优良的光化学特性将有利于其在光热器件的制造及化学生物领域的应用。 相似文献
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以柠檬酸和尿素为碳源和氮源,采用固态法一步合成出量子产率高达23%的荧光碳点。表征结果表明,所合成的荧光碳点为平均粒径为3~4 nm的球形,表面富含羟基、羧基和胺基等基团。此外,碳点的XRD谱图显示出无定型碳的特征峰。以所制备的碳点为荧光探针,基于碳点和阿霉素之间的共振能量转移而猝灭碳点的荧光,建立了阿霉素定量分析新方法。实验中考察了溶液的pH值和孵化时间的影响。在最佳实验条件下,阿霉素浓度在0.67~16.67 μg·mL-1范围之间与碳点的荧光猝灭值ΔF呈良好的线性关系(R2=0.995),检出限为0.22 μg·mL-1,回收率为83.0%~89.2%,相对标准偏差小于2.5%(n=5)。尿样中常见物质对测定干扰较小,显示出所建立的方法具有较好的选择性。 相似文献
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In this paper, a fast and simplest one-pot tactic was used to synthesis fluorescent oxygen doped carbon dots from Tween-20 (TTO-CDs) is reported. The TTO-CDs were microwavically synthesized by using Tween-20 as both the carbon precursor and the oxygen dopant as well. The surface morphology, crystalline and/or amorphous nature, composition and optical assets of synthesized TTO-CDs were studied by means of existing techniques. From the results, it was confirmed that the as-synthesized TTO-CDs are amorphous in nature, monodispersed, sphere-shaped and the typical particle size range is 5?±?1.5 nm. The synthesized TTO-CDs emits strong blue fluorescence at 390 nm under excitation of 335 nm. Most interestingly, the excitation dependent emission property of synthesized TTO-CDs was exposed from fluorescence results. The synthesized TTO-CDs have quantum yield of about 14% against quinine sulfate as reference standard. The biotoxicity of synthesized TTO-CDs on HeLa cells was assessed through cytotoxicity assay. These results implied that the fluorescent TTO-CDs showed less biotoxicity, and further which was efficaciously applied as a multicolor staining and bioimaging probe for the confocal imaging of HeLa cells. 相似文献
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Mohammad Saeid Hosseini Somayeh Khorashahi Navid Hosseini 《Journal of fluorescence》2016,26(3):867-874
The CdSe quantum dots (QDs) capped with 2-mercaptonicotinic acid (H2MN) were prepared through a controllable process at 80 °C. The prepared QDs were characterized by XRD, TEM, IR, UV–Vis and fluorescence (FL) techniques. It was found that the QDs were nearly mono-disperse with the diameters in the range of 8–10 nm. These QDs are capable to exhibit strong FL even in concentrated acidic media. They exhibit an enhanced fluorescence in the presence of Cr(VI), which was used for the determination of Cr(VI) in water samples. The linear range was found to be 1?×?10?7–6.0?×?10?6 M with the RSD and DL of 0.92 % and 5?×?10?8 M, respectively. Except that Ca2+ and Fe3+ which can be eliminated through a simple precipitation process, the other co-existent ions present in natural water were not interfered. The recoveries obtained for the added amounts of Cr(VI) were in the range of 96.9–103.2 %, which denote on application of the method, satisfactorily. 相似文献
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盐酸表阿霉素与牛血清白蛋白相互作用的研究及药物在血清与尿样中含量的测定 总被引:10,自引:0,他引:10
应用荧光光谱法研究了盐酸表阿霉素与血清白蛋白之间的相互作用,求得它们之间的结合常数KA=2.342×10~4(t=25℃),KA=1.993×10~4(t=35℃),KA=1.638×10~4(t=45℃),以及金属离子对结合常数的影响,确定了药物与血清白蛋白之间的相互作用力,并根据Forster非辐射能量转移理论求出给体-受体间的结合距离r=4.25 nm和能量转移效率E=0.018。又进一步在生理条件下成功的测定了药物在血清与尿样中的含量。 相似文献
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Pirsaheb Meghdad Mohammadi Somayeh Khodarahmi Reza Hoseinkhani Zohreh Mansouri Kamran Payandeh Mehrdad 《Journal of fluorescence》2022,32(5):1733-1741
Journal of Fluorescence - In this research, DNA-modified carbon dots (CDs) were exploited to construct a fluorescence assay for breast cancer genes (BRCA1, a potential marker for cancer diagnosis)... 相似文献
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Vaibhavkumar N. Mehta Shiva Shankaran Chettiar Jigna R. Bhamore Suresh Kumar Kailasa Ramesh M. Patel 《Journal of fluorescence》2017,27(1):111-124
In this work, highly luminescent carbon dots (CDs) were synthesized by the hydrothermal method at 170 °C for 12 h using pasteurized milk as a carbon source. The prepared CDs exhibited bright blue fluorescence under UV light illumination at 365 nm. The CDs show fluorescence life time of ~4.89 ns at excitation wavelength of 370 nm. The effect of different solvents on the fluorescence property of CDs was also investigated. The lisinopril (Lis)-loaded CDs were fabricated by self-assembly of lisinopril on the surfaces of CDs, which were characterized by UV-visible and FT-IR spectroscopic techniques. The controlled release of lisinopril from the Lis-CDs was realized at pH values of 5.2, 6.2 and 7.4, respectively. The results of the cytotoxicity and confocal laser scanning microscopic images indicate that the Lis-CDs were successfully uptaken by HeLa cells without apparent cytotoxicity. The synthesized CDs show great potential as drug vehicles with good biocompatibility, sustained release of lisinopril from CDs, indicating that the CDs can act as a promising drug delivery system for therapeutic delivery and/or bioimaging applications. 相似文献
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V. K. Gasparyan 《Journal of fluorescence》2014,24(5):1433-1438
Effects of various factors on synthesis and fluorescent properties of CdSe quantum dots were studied. It was shown that variation of pH, stabilizer and concentration of precursors brings to obtaining of quantum dots with various fluorescent properties. The nanoparticles prepared were conjugated with rabbit antibodies to C-Reactive protein and C-Reactive protein for competitive immunoassay for determination of CRP. It was shown that interaction of these dots as a result of antigen-antibody reaction brings to resonance energy transfer and these changes in fluorescence spectra correlate with concentration of CRP. This approach permits to determine CRP in range between 4–100 ng 相似文献
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《光谱学快报》2013,46(4-5):405-417
Abstract Digestion methods such as dry and wet ashing and microwave oven were examined at various conditions to determine a rapid, reliable, and simple digestion procedure for yogurt. Digestion by microwave oven was found to be an excellent method in comparison with dry and wet ashing methods when only Al and Zn in yogurt samples were determined. Iron in this matrix is not completely digested by the microwave oven method at the examined conditions. From the obtained results, yogurt can also be a good source of essential nutrients such as minerals in human diet, especially zinc. Aluminum concentrations in yogurt samples fermented in Al containers were found to be significantly higher than in plastic containers. Al concentrations of yogurt taken from the bottom of the container were found to be higher than from the center and top of Al containers. The determinations of metals were carried out via an atomic absorption spectrophotometer using calibration curve and standard additions methods. Aluminum concentrations in yogurt samples produced in big production centers were found to be significantly higher than the other yogurt samples produced in‐house when plastic containers were used. 相似文献
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Ryosuke Nakahara Satomi Kashitani Kumi Hayakawa Yuuki Kitani Takako Yamaguchi Yoshikazu Fujita 《Journal of fluorescence》2009,19(5):769-775
A fluorophotometric method for the determination of hydrogen peroxide (H2O2) using fluorescin was developed. This method was based on the oxidative reaction of fluorescin, a colorless, non-fluorescent
lactoid fluorescein, by H2O2 to give highly fluorescein fluorescence emission. In the determination of H2O2, the calibration curve exhibited linearity over the H2O2 concentration range of 1.5–310 ng mL−1 at an emission wavelength of 525 nm with an excitation of 500 nm and with relative standard deviations (n = 6) of 2.51%, 2.48%, and 1.31% for 3.1 ng mL−1, 30.8 ng mL−1, and for 308 ng mL−1 of H2O2, respectively. The detection limit for H2O2 was 1.9 ng mL−1 six blank determinations was performed (ρ = 6). This proposed method was applied to detection of other reactive oxygen species and nitrogen species (ROS/RNS) such
as singlet oxygen (1O2), hydroxyl radical (•OH), peroxynitrite (ONOO−) etc., and it was possible to detect them with a high sensitivity. In addition, this proposed method was applied to the recovery
tests of H2O2 in calf serum, human saliva, rain water, and wheat noodles; the results were satisfactory. 相似文献
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Jingyun Ma Hua Tan Hong Liu Yimin Chao 《Particle & Particle Systems Characterization》2021,38(3):2000288
Si-based materials possess huge potential as an excellent anode material for Li-ion batteries. However, how to realize scalable synthesis of Si-based anode with a long cycling life and high-performance is still a critical challenge. Here a water-in-oil microemulsion process followed by UV illumination, calcination, and hydrothermal method to produce yolk-shell Si@void@C embedded in interconnected 3D porous carbon network architecture using silicon nanoparticles is reported. As a result, the sample Si@void@C/C-2 electrode has achieved a reversible capacity of 1160 mA h g−1 at 0.2 A g−1 after 300 cycles and a stable long cycling life of 480 mA h g−1 at 1 A g−1 after 1000 cycles. A full battery with the synthesized anode shows a capacity of 128 mA h g−1 at 0.2 A g−1 as well as good cycling stability after 1100th cycles. Such excellent electrochemical performance is ascribed to its unique structure, the yolk-shell void space, highly robust carbon shells and interconnected porous carbon nets that can improve the conductivity of the electrode, buffer the volume expansion, and also suppress Si nanoparticles stress variation. This water-in oil system makes it possible for mass production of environmentally friendly synthesis of core–shell structure. 相似文献
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Ravi Kumar Vuradi Srishailam Avudoddi Venkat Reddy Putta Laxma Reddy Kotha Praveen Kumar Yata Satyanarayana Sirasani 《Journal of fluorescence》2017,27(3):939-952
Three ruthenium(II) polypyridyl complexes, [Ru(phen)2(mip)](ClO4)2 (1) (phen =1,10-Phenanthroline), [Ru(bpy)2(mip)](ClO4)2 (2) (bpy = 2,2’bipyridyl) and [Ru(dmb)2(mip)](ClO4)2 (3) (dmb = 4, 4′-dimethyl 2, 2′-bipyridine), were synthesized with an intercalative ligand mip (2-morpholino-1H-imidazo[4,5-f][1, 10]phenanthroline) and characterized by 1H, 13C–NMR, IR, UV-vis, mass spectra and elemental analysis. pH effect, ion selectivity (cations, anions) and solvent sensitivity of complexes were studied. The interaction of these complexes with DNA was performed using absorption, emission spectroscopy and viscosity measurements. The experimental results indicated that the two complexes interacted with calf thymus DNA (CT-DNA) by intercalative mode. BSA (Bovine Serum Albumin) protein binding of these complexes was studied by UV-visible and fluorescence techniques. The binding capacity of these complexes was explained theoretically by molecular docking method. 相似文献
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Mahmoud A. Omar Abdel-Maaboud I. Mohamed Sayed M. Derayea Mohamed A. Hammad Abobakr A. Mohamed 《Journal of fluorescence》2017,27(2):473-482
A novel, sensitive and selective spectrofluorimetric method has been developed and validated for determination of silodosine (SLD) in its dosage form and human plasma. The method is based on nucleophilic substitution reaction of SLD with 5-(dimethylamino) naphthalene-1-sulfonyl chloride (dansyl chloride) in presence of 5.0 × 10?4 M sodium carbonate (pH 10.50) to yield a highly fluorescent derivative that was measured at 435 nm after excitation at 347 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence-concentration plot was rectilinear over the range 30.0–200.0 ng ml?1, with a correlation coefficient of 0.9979. The limits of detection (LOD) and quantification (LOQ) were found to be 5.44 and 16.47 ng ml?1, respectively. The proposed method was validated according to ICH guidelines, and successfully applied to the assay of commercial capsules as well as content uniformity testing. The high sensitivity of the proposed method allowed its successful application to the analysis of SLD in spiked human plasma with % recovery of 92.88 ± 1.05–100.73 ± 0.75%, (n = 6). The application of the proposed method was further extended to stability studies of SLD after exposure to different forced degradation conditions, such as acidic, alkaline and oxidative conditions, according to ICH guidelines, where this work describe the first attempt for selective spectrofluorimetric determination of silodosine in plasma and in the presence of its oxidative degradation. 相似文献