Enhancement Effect of Gold Nanoparticles on the Bioactivity of Hydrogen-producing Microbe

1 IntroductionGold nanoparticles have attracted considerable atten-tionin manyfields duetotheir some special properties al-though goldis very popularfor beingchemicallyinert[1-3].For example ,gold nanoparticles as amplificationtags havebeenthe subject of research directed at gene analysis[4]and antibody or antigen detection[5-7]due to the large di-electric constant ,ease of preparation,andits biocompati-bility[8].Nanoparticles in the range of 1-10 nmin diameterwould display electronic structur…     

羟基磷灰石纳米粒子对肝癌细胞PCNA表达的影响

为了研究羟基磷灰石(HAP)纳米粒子对肝癌细胞增殖细胞核抗原表达的影响,采用均匀沉淀法制备了均匀分散的纳米尺度的HAP纳米粒子。以0.56 mmol/L的HAP纳米粒子与Bel-7402肝癌细胞作用后,采用流式细胞技术检测细胞周期时相的变化,行免疫细胞化学法PCNA染色,形态学观察和定量分析细胞的PCNA表达。结果显示HAP纳米粒子能使Bel-7402细胞的细胞增殖周期阻滞于G1期,PCNA表达降低,与对照组比较有显著性差异(P<0.01)。HAP纳米粒子可能通过抑制PCNA的表达,起到抑制肝癌细胞增殖的作用。     

Au/SiO_2复合薄膜的紫外光还原制备与光吸收性能

通过溶胶-凝胶法,利用紫外光辐射还原金(Au)得到了高均匀性Au/SiO2复合薄膜,并用SEM、TEM、XRD、UV-Vis光谱等手段对薄膜样品进行了性能表征,讨论了紫外光对金纳米粒子的还原机理。XRD结果表明,均匀分散于非晶SiO2中的Au纳米粒子呈现出面心立方多晶相;SEM结果表明,所得到的Au/SiO2复合薄膜中,纳米颗粒的尺寸较小,分布均匀;复合薄膜的UV谱表明,Au纳米粒子的表面等离子共振吸收峰随着焙烧温度的增加以及nAu/nSi的改变,从585nm附近逐渐红移至600nm附近,并逐渐增强,同时,nAu/nSi较大的3个薄膜样品分别在820,900和830nm附近的近红外区出现了吸收。     

纳米金放大法荧光检测乙肝病毒HBV-DNA

利用纳米金放大的方法,将修饰荧光团的信号DNA连接在纳米金表面,纳米金通过HBV-DNA与磁珠连接,1,4-二硫苏糖醇(DTT)可以替代信号DNA连接在纳米金表面,将荧光素标记的信号DNA释放于溶液中,测定溶液的荧光强度可以得到HBV-DNA的浓度。通过条件优化实验确定了最佳实验条件:生物素与亲和素最佳结合时间为25min,DNA的最佳杂交时间为15min。测定HBV-DNA的线性范围为3.0×10-13～1.2×10-12mol·L-1,线性相关系数r=0.991 4,检测限为2.18×10-14mol·L-1(S/N=3)。     

纳米磷灰石对肝癌癌基因表达的影响

研究纳米磷灰石体外对人肝癌细胞系Bel-7402的作用机理。应用均相共沉淀法室温下合成纳米磷灰石，用透射电镜和电位粒度仪进行表征；利用透射电镜、原位杂交细胞化学检测其对人肝癌细胞系Bel-7402 c-myc和p53基因表达的影响。纳米磷灰石呈均匀分散的针状颗粒．粒径范围在67．5～88．3nm之间。可使肝癌细胞体积增大，胞质空泡化，线粒体肿胀；部分细胞核内染色质分散，凝集在核膜周围，呈团块状，核膜间隙不等，胞浆溶解。抑制c-myc和增强p53基因的表达。纳米磷灰石在体外通过下调c-myc和上调p53基因的表达，致肝癌细胞胀亡。     

纳米NaYF4：Nd^3＋、Dy^3＋材料的上转换光学特性

制备了Nd^3＋和Dy^3＋掺杂立方相NaYF4上转换发光纳米晶体,用XRD、荧光光谱等测量手段对纳米颗粒的结构和发光性能进行表征,探讨Nd3’和Dy¨的掺杂比例对上转换发光的影响．利用776nm红外光激发样品,NaYF4：Nd^3＋,Dy^3＋实现蓝、绿上转换发光,出现Dy^3＋特征峰：479nm、574nln上转换发射峰．探讨基质NaYF4中Nd^3＋对Dy^3＋的敏化作用及上转换机制．     

In-situ growth of silver nanostructure on quartz glass substrates

Silver nanostructure compact aggregates on the surface of quartz glass substrates were synthesized by small gold seeds with the assistance of poly vinypyrrolidone (PVP) and irradiation of fluorescent lamp. The formation mechanism of silver nanostructure was proposed. The results show that both the PVP and the light irradiation are the keys to in-situ growth of silver nanostructure on quartz glass substrates. The silver nanostructure of the substrates which finally grow up to 150 nm after 20 h irradiation exhibits irregular shape, and some of nanoparticles stack to form bilayer. A new broad band appears in the absorption spectra of the substrates due to the interparticle dipole-dipole coupling of surface plasmon resonance response of the triangular silver nanoplate particles, which red shifts 600–800 nm as the particles grow up. The substrates have an emission band centered at 400 nm on their fluorescence spectra, and the fluorescence intensity shrinks as the average size of the silver nanostructure increases. The strongest SERS signal of SERS-active substrate is fabricated after 16 h.     

Aggregation of gold nanoparticles and DNA damage by atomic force microscopy

The plasmid DNA binding and cleavage activities with gold nanoparticles (Au-NPs) were investigated by the integrated tools of UV-vis spectroscopy, atomic force microscopy (AFM), and DNA electrophoresis. The results showed that the absorbance of Au-NPs decreased at 520 nm and a new absorption peak at 570 nm was found, as the DNA concentration increased, which indicated the particle aggregation. AFM experiments showed that DNA-induced particle aggregation originated from the strong interactions between DNA and Au-NPs, that is, the adsorption of DNA onto the Au-NPs surface would result in particle aggregation. After a short period of time, the Au-NPs were easier to aggregate in the presence of the higher concentration of DNA. At the early stage of incubation, the DNA double helix conformation was substantially changed by particles. The electrophoresis manifested the absorption and damage appeared on the native DNA molecules. With a longer treating time, the molecules were broken into fragments. The DNA damage was deemed to be a gradual process. The nonspecific interactions between DNA and Au-NPs resulted in the binding of DNA to the Au-NPs surface. Consequently, not only Au-NPs were aggregated but also DNA was damaged.     

HPV16型免疫胶体金诊断试纸条的制备

建立一种快速、准确、简便检测高危型人乳头瘤病毒16型的胶体金诊断试纸条,以用于宫颈癌的早期筛查。用柠檬酸三钠还原法制备了酒红色的30 nm胶体金颗粒,胶体金颗粒标记的单抗的实际标记量为6μg/mL。选用了2种稳定剂BSA和PEG20000获得了稳定的金标抗体溶液。实验结果表明:第7种样品垫处理液和第7种结合垫处理液处理样品垫和结合垫组装的试纸条效果最好;试纸条检测HPV16E6蛋白为阳性,检测HPV16L1蛋白为阴性。     

Optical properties of Au nanoparticles coated on surface of glass or anodic aluminum oxide template

Au nanoparticles coated on the surface of glass (Sample A) or on anodic aluminum oxide template surface (Sample B) were prepared using titanium dioxide sol-gel doped with chloroauric acid and with a reduction process. FE-SEM, UV-Vis spectrum and Fluorescence spectrum tests show that Au nanoparticles have been distributed randomly on the surface of glass, while deposition occurs on the surface of regular hollows for anodic aluminum oxide template. A sharp absorption peak appears at the wavelength of 536 nm for sample B, while there is a red shift, with a broader peak for sample A. A distinct fluorescence emission at the wavelength of 633 nm is detected for sample A, but no noticeable fluorescence emission has been found for Sample B. The results indicate that the microstructure and optical properties of Au nanoparticles can be modulated by different substrate.     

纳米金/琼脂糖复合凝胶制备及其催化性能

以琼脂糖作为模板、稳定剂和还原剂,通过一步法合成了纳米金粒子及纳米金/琼脂糖复合凝胶,对纳米金粒子进行了表征,并以对硝基苯酚催化还原为模型反应研究了纳米金/琼脂糖复合凝胶的催化性能.结果表明,纳米金粒子为球状,粒径为1~10nm,分布较均一;纳米金/琼脂糖复合凝胶表现出明显的催化活性,在实验条件下完全反应时间约为30min.在重复利用实验中,该复合凝胶的催化性能随使用次数增多有一定下降.通过琼脂糖和氯金酸一步法制备纳米金/琼脂糖复合凝胶,方法简单、使用方便、后处理容易,为新型纳米金属催化剂的设计、合成及应用提供了新的思路.     

棉织物水热法纳米二氧化钛表面改性

采用水热合成技术,使用硫酸钛和尿素直接在棉织物纤维表面包覆纳米TiO2颗粒薄膜.借助SEM、XRD、FT-IR、DSC和TG对棉纤维改性前、后的表面形貌、结构和热学性能进行了表征,并测定了织物反射光谱、拉伸、吸水和光催化活性.研究结果表明,棉织物经过硫酸钛尿素水热改性之后,纤维表面包覆了一层锐钛矿型纳米TiO2颗粒薄膜,由平均粒径2.0 nm的纳米颗粒聚集成100 nm以上的球形颗粒,并通过物理吸附方式附着在纤维表面.改性后的织物热起始分解温度和吸热熔融峰温度均有所降低.具有抗紫外线能力和光催化活性,吸水性能也有所增强,但由于织物尺寸发生收缩,断裂强力有所减小,断裂伸长率有所增加.     

纳米金在生物标记分析中的应用进展

论述了纳米金粒子的特性、制备方法及其在免疫分析、DNA识别与检测、生物传感器和生物芯片中具体的应用原理和进展情况,并展望了纳米金在生物标记领域中广阔的应用与发展前景。     

纳米金在生物标记分析中的应用进展

论述了纳米金粒子的特性、制备方法及其在免疫分析、DNA识别与检测、生物传感器和生物芯片中具体的应用原理和进展情况，并展望了纳米金在生物标记领域中广阔的应用与发展前景。     

PLD制备FePt：MgO薄膜的结构及线性光学性能研究

采用脉冲激光沉积法（PLD）制备了FePt：MgO多层复合薄膜。采用高分辨透射电子显微镜（HRTEM）分析了薄膜的结构;采用紫外可见分光光度计分析了薄膜的线性光学性能。HRTEM分析表明基质MgO在单晶MgO衬底上同质外延生长,而FePt纳米颗粒周期性均匀地自组织嵌埋在MgO基质中。HRTEM的快速傅里叶变换（FFT）图表明,FePt纳米颗粒为富Pt的面心立方（FCC）结构的FePt3,其晶格常数αFePt3=3.90 。（1。=0.1 nm）。MgO基质与FePt纳米颗粒的界面分析表明,它们的界面处几乎不存在非晶层,只在FePt纳米颗粒与MgO基质的晶界线附近有少量的刃型位错。薄膜的紫外可见吸收谱结果表明,低脉冲数样品具有远紫外增透作用,高脉冲数样品存在3个表面等离子激元共振吸收峰,随FePt沉积脉冲数增加,吸收峰位置均发生红移,峰强逐渐减弱,峰强比规律变化。     

核壳结构Au@SnO2的制备及其低温下的正丁醇气敏性能

以SnCl₄·5H₂O和HAuCl₄·3H₂O为原料,以L-半胱氨酸为连接剂,通过水热法制备Au@SnO₂核壳结构纳米颗粒。由透射电子显微镜和X射线衍射结果发现二氧化锡（SnO₂）与金（Au）颗粒的平均粒径分别为4.9 nm和10.5 nm。SnO₂颗粒堆积在Au核表面形成了具有多孔壳结构的复合材料,比表面积达到178.82 m²/g,总孔隙体积为0.165 1 cm³/g。Au@SnO₂核壳结构的存在使得传感器对正丁醇具有优异的气敏性能,在80 ℃时的灵敏度达到8 669.15,检测极限达到3.9×10^-3 g/m³,显著提高了SnO₂的灵敏度,并降低了最佳工作温度。     

苯乙烯 - 马来酸酐无规共聚物/银纳米微粒的合成及表征

金属纳米材料能够产生量子尺寸效应及表面效应，在许多领域具有很好的应用前景.以DMF(N,N-二甲基甲酰胺)为溶剂及还原剂，苯乙烯-马来酸酐无规共聚物为大分子稳定剂，在不同的反应条件下，合成制备了银纳米微粒.通过紫外-可见吸收光谱、透射电子显微镜等测试手段对所合成的纳米银样品进行了表征.结果表明：通过上述反应所得到的银纳米微粒的DMF溶液可以在420 nm处出现纳米银所具有的特征吸收峰，增加了反应前驱体浓度及反应时间，使银纳米微粒的特征吸收峰变得更加明显.透射电子显微镜的结果表明，所得到的银纳米微粒具有较窄的尺寸分布，从而证明苯乙烯-马来酸酐无规共聚物可以对纳米银表面进行较好的修饰.     

Preparation, optical properties and cell staining of water soluble amine-terminated PAMAM G2.0-Au nanocomposites

The solution chemical and optical characteristics of formation of amine-terminated polyamidoamine dendrimer G2.0（NH2-PAMAM G2.0）-Au nanocomposites in the aqueous solution of NH2-PAMAM G2.0 at various mole ratios of Au（Ⅲ） to NH2-PAMAM G2.0 were studied by both UV-visible spectrometry and fluorospectrometry. The NH2-PAMAM G2.0-Au nanocomposites, with a type of structure in which one Au nanoparticle is surrounded by several NH2-PAMAM G2.0 dendrimers, emit strong bluish violet fluorescence, and are uniform, water soluble and biocompatible as well as very stable in frozen conditions. The size of gold nanoparticles in the nanocomposites is about 2.5 nm and decreases with the increase of NH2-PAMAM G2.0 concentration. The NH2-PAMAM G2. 0 plays an important role in acting as host or micro-reactor for Au（Ⅲ） before Au（Ⅲ） reduction and acting as dispersant and stabilizer for gold nanoparticles after Au（Ⅲ） reduction. Preliminary experiments of cells staining to human embryonic lung fibroblast cell lines show that the NH2-PAMAM G2.0-Au nanocomposites can be used as optical imaging markers for bioanalyses and medical diagnoses.     

Inhibition of inositol-1-phosphate synthetase in Mycobacterium tuberculosis by chitosan-antisense nanoparticles

Oligodeoxynucleotides (ODNs) were combined with the biodegradable polymer chitosan to form chitosan-ODN nanoparticles by complex coacervation, in order to improve the stability and intracellular penetration. The diameter of the nanoparticles was light strength size and ranged between 60 and 219 nm with a mean value of 132 nm, while zeta potential was between +12 and +20 mV at pH 5.5. The chitosan-ODN nanoparticles could partially protect the encapsulated ODN from nuclease degradation. Moreover, chitosan-ODN nanoparticles were much more effective in inhibiting the proliferation of M.tuberculosis than free ODN. Funded by the National Natural Science Foundation of China (No. 30170051 and No. 30328031)     

Direct synthesis and spectrum analysis of CeO2 nanoparticles deposited on carbon nanotubes

A novel method of direct synthesis of CeO₂ nanoparticles onto multi-walled carbon nanotubes (MWNTs) was developed with advantages of simplicity, ease of scale-up, and low costs. The size of CeO₂ particles deposited on the MWNTs was less than 6 nm. SEM and TEM were employed to analysis the CeO₂ coated MWNTs, and the properties of FTIR spectrum and UV-vis absorption spectrum were investigated. The functional groups on the MWNTs obtained by nitric acid treatment play an important role on the deposition of the CeO₂ particles. The carbon nanotubes possess broadened UV absorption function after being coated with CeO₂ nanopartilces. Funded by the National Natural Science Foundation of China (No. 90406024), NSF Project of CSTC (No. 2006BB4241) and Chongqing University Postgraduates’ Science and Innovation Fund (No. 200701Y1A0210207)