HRP/PET自组装膜及其在光度分析中的应用

利用静电自组装技术在阴离子化的PET表面组装了单分子层的HRP酶膜,通过AFM对膜表面形貌进行了分析.由于HRP的沉积,PET薄膜在组装HRP前后,表面形貌发生了较大的变化,表面粗糙度(Rms)由0.645 nh增加到2.580 nm,表面酶颗粒高度为3.3 nm,与HRP的XRD数据(4.028 nm×6.746 nm×11.711)基本相符.制备的酶自组装膜在4℃的低温条件下密封保存.该酶膜在最初的一个星期内酶活性下降较快,之后酶活性则基本保持不变,150天后仍能保持最初时的80%以上的活性;而在常温下,酶膜很快失去活性.表明自组装HRP/PET酶膜在低温下具有很好的保存稳定性.以微量比色皿为反应容器,考察了酶膜与H2O2的显色反应动力学,该反应的表观米氏常数Kapp m=3.2×10-5 mol/L(相对于H2O2底物),显色反应在5 min内完成.在所考查的H2O2浓度浓度区间内(8.8×10-6～8.8×10-5mol/L),酶膜所催化的显色反应产物的吸光度与其浓度之间存在良好的线性关系,对样品中H2O2测定的回收率为96.5%～101.1%.     

预混合自组装辣根过氧化物酶生物活性膜及其催化活性研究

以阳离子化的辣根过氧化物酶 (HRP)和阴离子聚苯乙烯磺酸钠 (PSS)的预混合溶液 ,与阳离子聚电解质聚二甲基二烯丙基氯化铵 (PDDA)通过逐层组装 ,在阴离子化聚对苯二酸乙二酯 (PET)表面构建了多层生物活性膜 .用紫外 可见光谱仪 (UV Vis)和原子力显微镜 (AFM)研究了交替自组装膜的结构和表面形膜 ,并测定了自组装膜的生物催化活性 .结果表明 ,预混合溶液中的PSS与HRP一起沉积在PDDA膜层上组装成 (PSS+HRP)膜层 ,且每层中PSS和HRP的比例一致 ;(PSS +HRP)膜层呈条状分布 ,膜表面较为平整 ;多层膜中的HRP催化H2 O2 与 4 氨基安替比林的显色反应的表观米氏常数为 9 7× 10 - 5mol·L- 1 (相对于H2 O2 底物 ) ,较溶液中 (1 5 2× 10 - 4mol·L- 1 )的小 .     

糖蛋白-凝集素自组装构筑有序膜及在酶电极的应用

利用糖蛋白-凝集素的识别作用交替沉积伴刀豆球蛋白（Con A）与辣根过氧化物酶(HRP)制备酶自组装多层膜，用原子力显微镜（AFM）观测了自组装膜的表面形貌、表面粗糙度； AFM和椭圆偏振研究测定了自组装膜的厚度.结果表明, Con A和HRP膜厚分别为9.0和4.6 nm，与两者的晶体衍射结果一致，说明生物识别自组装方法能很好地保持分子的原有形态.以亚甲蓝（MB）溶液为介体，用循环伏安法测定了表面修饰了三层（Con A/HRP）自组装膜的金电极对H2O2的电化学催化还原作用，在H2O2浓度为0.2～1.0 mmol•L－1时，响应电流对H2O2浓度变化成线性，酶电极灵敏度为24.0 mA•mol－1•L，表观米氏常数为4.2 mmol•L－1.     

在N,N-二甲基甲酰胺/水混合溶剂中制备偶氮聚电解质自组装膜

利用静电吸附逐层自组装方法在有机溶剂N,N二甲基甲酰胺(DMF)和H2O的混合介质中制备非水溶性偶氮聚电解质自组装多层膜.研究了DMF和H2O的配比对自组装膜生长、结构与表面形态的影响.结果表明,DMFH2O的混合溶剂是非水溶性偶氮聚电解质自组装的理想介质,二者之间的配比对自组装膜的生长速度,膜的结构以及表面形态均有显著影响.随着混合溶液中DMF含量的升高,自组装膜的生长速度逐渐下降但线形生长关系越来越好,所得自组装膜中偶氮生色团的H聚集程度逐渐下降,而且自组装膜的表面越来越平整.     

辣根过氧化物酶活性膜结构及生物电催化性能

通过分子沉积法研究了在聚对苯二甲酸乙二醇酯（PET）表面及金电极表面组装辣根过氧化物酶（HRP）/聚对苯乙烯磺酸钠（PSS）多层生物活性膜，用原子力显微镜(AFM)研究了组装膜的表面形貌，并研究了组装膜的形貌、粗糙度和活性关系.应用循环伏安法（CV）研究了组装HRP膜后电极对H2O2的电化学催化还原作用.实验发现，采用亚甲基蓝（MB）溶液为介质，在H2O2浓度为0.2～5.0 mmol•L－1时，其响应电流对H2O2浓度变化基本呈线性.     

反应离子刻蚀和自组装分子膜构建硅基底疏水与超疏水表面

采用反应离子刻蚀技术在Si(100)表面加工微米级圆柱阵列, 采用自组装技术分别制备了3种硅烷自组装分子膜. 结果表明, 采用反应离子刻蚀构建出的4种微米级圆柱阵列结构规整, 其直径为5 μm, 高度为10 μm, 间距为15~45 μm. 沉积自组装分子膜后, 试样表面的水接触角显著增大, 其中沉积1H,1H,2H,2H-全氟癸基三氯硅烷(FDTS)自组装分子膜接触角最大, 1H,1H,2H,2H-全氟辛烷基三氯硅烷(FOTS)次之, 三氯十八硅烷(OTS)最小. 测得的接触角大于150°时接近Cassie方程计算的接触角, 而小于150°时接近Wenzel方程计算的接触角. 改变圆柱阵列的间距和选择不同的自组装分子膜, 可以控制表面接触角的大小. 原子力显微镜(AFM)观测结果显示, 沉积自组装分子膜可以产生纳米级的团簇. 由微米级圆柱阵列和纳米级自组装分子膜构成的表面结构使Si试样表面接触角最大可达156.0°.     

基于纳米自组装技术的功能化溶胶-凝胶过氧化氢生物传感器

结合功能化溶胶-凝胶(sol-gel)网络结构、自组装技术和纳米粒子效应,提出一种生物传感界面构建方法.利用自组装技术在玻碳电极表面组装氨基化sol-gel膜,通过与自组装膜间的强烈作用将纳米金粒子固定于sol-gel网络中,再通过静电吸附作用实现辣根过氧化物酶(HRP)在纳米金粒子表面的固定化,构建纳米自组装HRP传感界面.将制备的传感器用于对H2O2的催化还原,很好地保持了酶的生物活性,改善了传感器的灵敏度.     

自组装超薄膜修饰Ta2O5介质膜及其特性研究

采用静电自组装方法在五氧化二钽(Ta2O5)介质氧化膜上制备了聚二烯丙基二甲基氯化铵(PDDA)/聚苯乙烯磺酸钠(PSS)和聚二烯丙基二甲基氯化铵/聚-3,4-乙烯二氧噻吩-聚苯乙烯磺酸钠(PEDOT-PSS)超薄膜.研究了两种自组装超薄膜在Ta2O5介质氧化薄膜上的组装特性.结果表明两种自组装膜能够稳定地组装于Ta2O5介质膜表面,并有效降低薄膜的表面粗糙度.进一步研究了两种自组装超薄膜修饰的Ta2O5电容结构的电性能.结果表明静电自组装膜对Ta2O5介质膜表面进行修饰后,有效地隔离了介质氧化膜中的缺陷,降低了电容的漏电流并提高耐电压能力;研究还发现不同厚度的超薄膜对Ta2O5电容结构的耐压特性有不同程度的影响,较厚的薄膜可以更好地提高电容的耐压能力并降低漏电流,但会增加电容的等效串联电阻(ESR).另外,在相同薄膜层数的情况下,聚合物电解质PEDOT-PSS良好的导电性能降低了复合超薄膜的电阻,使得PDDA/PEDOT-PSS修饰的电容结构ESR值较低.     

血红蛋白作为过氧化物模拟酶催化测定过氧化氢

研究了牛血红蛋白 (Hemoglobin ,Hb)作为过氧化物模拟酶催化H2 O2 氧化隐性亮绿 (RecessiveBrilliantGreen ,RBG)显色反应的催化特性及反应条件。该体系在pH 5 .73的条件下形成的酶催化产物在 640nm处有最大吸收。体系测定H2 O2 时表观摩尔吸光系数为 7.1 5× 1 0 3L·mol-1·cm-1,测定H2 O2 检测限为 2 .8× 1 0 -6mol L。方法可用于天然水中H2 O2 的测定。     

铜卟啉-L-半胱氨酸自组装复合膜修饰电极的制备及电化学性能研究

利用电化学扫描法在L 半胱氨酸(Cys)自组装单分子膜修饰金电极表面现场制备了金属卟啉复合膜,对其进行SEM和ATR FTIR表征。修饰电极的支持电解质以及pH值对膜的稳定性和灵敏度有很大影响。铜卟啉 L Cys膜对H2O2具有良好的电催化还原特性,催化电流与H2O2浓度在1 0×10 6到3 0×10 5mol·L 1范围内线性关系,相关系数0 9995,检测限达1 0×10 7mol·L 1。     

Sc2MgGa2 and Y2MgGa2

Scandium magnesium gallide, Sc₂MgGa₂, and yttrium magnesium gallide, Y₂MgGa₂, were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo₂FeB₂‐type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc₂MgGa₂ was determined from single‐crystal diffraction intensities and the isostructural Y₂MgGa₂ was identified from powder diffraction data.     

Zur Kenntnis der Dialkalimetalldichalkogenide β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 und Rb2Te2

On Dialkali Metal Dichalcogenides β-Na₂S₂, K₂S₂, α-Rb₂S₂, β-Rb₂S₂, K₂Se₂, Rb₂Se₂, α-K₂Te₂, β-K₂Te₂ and Rb₂Te₂ The first presentation of pure samples of α- and β-Rb₂S₂, α- and β-K₂Te₂, and Rb₂Te₂ is described. Using single crystals of K₂S₂ and K₂Se₂, received by ammonothermal synthesis, the structure of the Na₂O₂ type and by using single crystals of β-Na₂S₂ and β-K₂Te₂ the Li₂O₂ type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na₂O₂ type to the Li₂O₂ type will be explained by means of the examples α-/β-Na₂S₂ and α-/β-K₂Te₂. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb₂S₂ is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.     

Thermal decomposition of Me3SnO2PCl2, Me2Sn(O2PCl2)2 and Ph3SnO2PCl2

TG and DTA studies on Me₃SnO₂PCl₂, Me₂Sn(O₂PCl₂)₂ and Ph₃SnO₂PCl₂ were carried out under dynamic argon atmosphere. The results show that the decomposition proceeds in different stages leading to the formation of Sn₃(PO₄)₂ as a stable product. This compound was characterized by IR spectroscopy. Decomposition schemes involving reductive elimination reactions were proposed.     

The alkali hypophosphites KH2PO2, RbH2PO2 and CsH2PO2

The structures of the hypophosphites KH₂PO₂ (potassium hypophosphite), RbH₂PO₂ (rubidium hypophosphite) and CsH₂PO₂ (caesium hypophosphite) have been determined by single‐crystal X‐ray diffraction. The structures consist of layers of alkali cations and hypophosphite anions, with the latter bridging four cations within the same layer. The Rb and Cs hypophosphites are isomorphous.     

Crystal Structures of [Bu2Sn(O2PPh2)2], [Ph2Sn(O2PPh2)2], and [PhClSn(O2PPh2)OMe]2. Raman Spectra of [Ph2Sn(O2PPh2)2] and [PhClSn(O2PPh2)OMe]2

[(n‐Bu)₂Sn(O₂PPh₂)₂] ( 1 ), and [Ph₂Sn(O₂PPh₂)₂] ( 2 ) have been synthesized by the reactions of R₂SnCl₂ (R=n‐Bu, Ph) with HO₂PPh₂ in Methanol. From the reaction of Ph₂SnCl₂ with diphenylphosphinic acid a third product [PhClSn(O₂PPh₂)OMe]₂ ( 3 ) could be isolated. X‐ray diffraction studies show 1 to crystallize in the monoclinic space group P2₁/c with a = 1303.7(1) pm, b = 2286.9(2) pm, c = 1063.1(1) pm, β = 94.383(6)°, and Z = 4. 2 crystallizes triclinic in the space group , the cell parameters being a = 1293.2(2) pm, b = 1478.5(4) pm, c = 1507.2(3) pm, α = 98.86(3)°, β = 109.63(2)°, γ = 114.88(2)°, and Z = 2. Both compounds form arrays of eight‐membered rings (SnOPO)₂ linked at the tin atoms to form chains of infinite length. The dimer 3 consists of a like ring, in which the tin atoms are bridged by methoxo groups. It crystallizes triclinic in space group with a = 946.4(1) pm, b = 963.7(1) pm, c = 1174.2(1) pm, α = 82.495(6)°, β = 66.451(6)°, γ = 74.922(6)°, and Z = 1 for the dimer. The Raman spectra of 2 and 3 are given and discussed.     

Electrochemical study of (NEt4)2Cl2FeS2MoS2 and (NEt4)2Cl2FeS2MoS2FeCl2

Summary The ability of [MoS₄]^2–, anions to be used as ligands for transition metal ions has been widely demonstrated, especially with Fe²⁺. The present study has been restricted to linear complexes such as (NEt₄)₂ [Cl₂FeS₂MoS₂] and (NEt₄)₂[Cl₂FeS₂MoS₂FeCl₂]. Their electrochemical properties are described: upon electrochemical reduction, these compounds yield MoS₂, as a black precipitate, and an iron complex in solution, assumed to be [SFeCl₂]^2–. The electrochemical reduction goes through two electron transfers, coupled with the breakdown of the molecular skeleton: a DISPl and an ECE mechanism. Depending on the solvent, the following equilibrium may be observed: [Cl₄Fe₂MoS₄]^2–[Cl₂FeMoS₄]^2–+FeCl₂. The equilibrium constant, K_D, was evaluated by differential pulse polarography. K_D is tightly related to the donor number of the solvent.     

Formal [(2+2)+2] and [(2+2)+(2+2)] nonconjugated dienediyne cascade cycloadditions

[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis.