Nano Au/TiO2 hollow microsphere membranes for the improved sensitivity of detecting specific DNA sequences related to transgenes in transgenic plants

Gold nanoparticles (nano Au)/titanium dioxide (TiO₂) hollow microsphere membranes were prepared on the carbon paste electrode (CPE) for enhancing the sensitivity of DNA hybridization detection. The immobilization of nano Au and TiO₂ microsphere was investigated with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The hybridization events were monitored with EIS using [Fe(CN)₆]^3−/4− as indicator. The sequence-specific DNA of the 35S promoter from cauliflower mosaic virus (CaMV35S) gene was detected with this DNA electrochemical sensor. The dynamic detection range was from 1.0×10⁻¹² to 1.0×10⁻⁸ mol/L DNA and a detection limit of 2.3×10⁻¹³ mol/L could be obtained. The polymerase chain reaction (PCR) amplification of the terminator of nopaline synthase (NOS) gene from the real sample of a kind of transgenic soybean was also satisfactorily detected. Supported by the National Natural Science Foundation of China (Grant Nos. 20635020 and 20375020), Doctoral Foundation of the Ministry of Education of China (Grant No. 20060426001) and Natural Science Foundation of Qingdao City (Grant No. 04-2-JZP-8)     

配位体修饰氟化锶纳米分层微球的可控合成

以硝酸锶为锶源,氟化钠为氟源,乙二胺四乙酸二钠(EDTANa2)为配位体,经微波促进合成了配位体修饰氟化锶纳米分层微球(1),其结构和形貌经XRD和SEM表征。物料比r[n(EDTANa2)∶n(Sr2+)]和反应温度(t)对1rt形貌影响较大。结果表明,在最佳反应条件[n(Sr2+)5 mmol,r=7,于120℃/600 W反应]下合成的17120分层清晰,分散性好,球体均匀,直径600 nm~800 nm。     

SiO_2微球固相萃取-火焰原子吸收光谱法测定水样中痕量Ag(Ⅰ)

本文通过水热合成法制备了SiO2微球,并研究SiO2微球在弱碱性条件下对Ag(Ⅰ)的吸附性能,建立了SiO2微球固相萃取-火焰原子吸收光谱法(AAS)测定痕量Ag(Ⅰ)的新方法。结果表明:在0.02mol·L-1 NaOH溶液介质中,Ag(Ⅰ)能被定量吸附,且能被2.0mL的12g·L-1硫脲-4%HCl混合液快速定量洗脱。方法的检出限(3σ)为0.59μg·L-1,富集倍数为50。该方法用于水样中痕量Ag(Ⅰ)的测定,加标回收率在95.0%~104.0%范围。     

Stimuli-responsive multilayer chitosan hollow microspheres via layer-by-layer assembly

Novel stimuli-responsive multilayer chitosan hollow microspheres with chitosan as the unique component have been fabricated by the sequential layer-by-layer electrostatic assembly technique from the sacrificial templates (polystyrene sulfonate, PSS) with chitosan (CS) as the polycation and carboxymethyl chitosan (CMCS) as the polyanion, respectively. Their hollow structure was confirmed by the TEM analysis. The DLS analysis indicated that the multilayer chitosan microcapsules were pH and ionic strength dual-responsive. Due to the biocompatibility of the single component chitosan used, the multilayer chitosan microcapsules are expected to be used in the controlled release of drugs.     

分步加压法测量薄壁空心玻璃微球的耐压能力

根据空心玻璃微球（HGM）耐内、外压能力与玻璃强度及形状因子的关系,用压力负荷分步增加的方法分别实验测量了直径为350μm～550μm、壁厚＜1.1μm的3种配方HGM的耐内、外压能力及HGM玻璃的杨氏模量和拉伸强度,并由强度测定值给出了不同直径与壁厚HGM的耐内、外压能力的计算式,分析了测量误差,提出了改进方案。     

基于计算机视觉的微球缺陷检测及分类方法

惯性约束聚变试验中,对大批量的聚变靶球的表面质量进行检测和分类是一项重要的工作。传统的人工检测分类方法效率低,精度差,难以满足实际需要。提出了一种基于计算机视觉的缺陷检测及分类方法。该方法在获取待测微球的显微图像之后,通过设置兴趣区域提取圆内部的像素点,并以此绘制灰度直方图。然后计算其累积分布函数,经归一化处理之后对分布函数进行分段线性拟合。最终根据拟合后的分布函数,提出均匀性和透光性两个参数用于定量表示微球的表面质量,很好地实现了光滑、粗糙和畸形三种类型的微球的分类。实验结果表明,该检测分类方法的准确率均在90%以上,处理1280960分辨率的包含20个微球的图像平均只需300 ms,准确高效,可扩展性强。     

掺钛空心玻璃微球制备技术

为实现惯性约束聚变靶用空心玻璃微球的均匀掺杂,采用溶胶-凝胶技术结合炉内成球法,以钛酸四丁酯为掺杂剂,对钛掺杂玻璃溶胶-钛掺杂玻璃凝胶-钛掺杂干凝胶粒子-钛掺杂空心玻璃微球（Ti-HGM）这一掺钛空心玻璃微球的制备方法进行了探索。实验结果表明：掺钛效应使空心玻璃微球壁厚均匀性、同心度有所降低,但对壁厚、直径控制基本无影响;Ti与Si原子分数比为2.23%的Ti-HGM掺杂基本均匀,近70%微球的保气半寿命在一个月以上。     

掺稀土元素的高折射率玻璃微球的制备与性能研究

制备了掺有稀土发光材料的高折射率玻璃微球,并用XRD、SEM等进行了表征.实验结果表明,该玻璃微球粒经分布范围窄,光学性能好,其折射率为1.93.用改造的显微拉曼光谱仪测量了微球上转换发光光谱,在其荧光光谱上发现了很强的形貌共振,并用光学微腔理论进行了解释.     

染料分子印迹聚硅氧烷的制备及性能研究（I）

分别以分散蓝和分散红两种染料为模板分子，3种硅烷偶联剂为功能单体，二氧化硅微球为载体，应用自组织法，制备了两种染料分子印迹的微球形聚硅氧烷。采用分光光度法，研究了分子印迹聚硅氧烷对各自模板分子的吸附性能及选择性识别性能。结果表明，与非印迹聚硅氧烷相比，染料分子印迹的聚硅氧烷对其模板分子具有较高的吸附能力，分子印迹聚硅氧烷的吸附速率也被讨论。     

N掺杂空心TiO2微球的合成与表征

采用无皂乳液聚合合成的聚苯乙烯(PS)微球为模板、氨水/三乙醇胺为催化体系, 通过溶胶-凝胶方法合成了PS/TiO₂(核/壳)复合微球, 然后通过煅烧制备了N掺杂、锐钛型空心TiO₂微球. 在反应体系中三乙醇胺扮演双重角色, 既是TiO₂生成及包覆过程的抑制剂又是空心TiO₂微球的N掺杂剂. 改变氨水、三乙醇胺和钛酸正丁酯用量可控制TiO₂壳的形态和尺寸. 氨水用量增加, PS/TiO₂复合微球的壳表面变得粗糙|三乙醇胺用量增加, 壳表面变得光滑|钛酸正丁酯用量提高导致壳层变厚. 改变三乙醇胺用量可调节空心TiO₂微球中的N掺杂量|N掺杂空心TiO₂微球具有可见光响应和光催化作用.