Micro—patterning of Copper Based on Photolithographed Self—assembly Monolayers

A new method has been develoed for fabrication of copper micro-pattern by selective chemical copper deposition based on photolithographed (3-mercaptopropyl)-trimethoxysilane (MPTS) self-assembly monolayers (SAMs). As confirmed by scanning electron microscopy (SEM), Cu closely replicated the mask features. The present approach makes this technic to be cheap and may be applicable to assembly of microelectronic circuits.     

Modification of gold electrode by self-assembled 2-mercapto benzothiazole for the determination of Hg2+

An electrochemical method was developed for the determination of mercury using polycrystalline gold electrode modified by self-assembled monolayers (SAMs) of 2-mercaptobenzothiazole (MBTH). Morphological and electrochemical characterisation of the self-assembled structure of MBTH was performed using atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS) measurements. The monolayer of MBTH has shown high affinity for Hg²⁺. The limit of detection for the determination of Hg²⁺ using the MBTH SAMs modified gold electrode was obtained as 0.421 μg L^?1. The pre-concentration of Hg²⁺ at open circuit potential is beneficial for the onsite monitoring of mercury concentration in water samples.     

Characterization of self‐assembled phenyl and benzyl isothiocyanate thin films on Au surfaces

Structures of self‐assembled monolayers (SAMs) prepared from benzyl isothiocyanate (BZIT) and phenyl isothiocyanate (PHIT) were comparatively investigated by means of surface enhanced Raman scattering (SERS) on gold nanoparticle surfaces. Both the molecules are assumed to have upright geometries binding via the sulfur atom, from the SERS spectral features. The broad and split bands at ～2100 cm^?1 could be ascribed to the combination band ν_9a + ν₁₂ of the phenyl ring vibrations through a Fermi‐resonance interaction with the ν₃(NCS) band in the neat‐liquid state. Such broad bands became quite symmetric upon adsorption on Au. UV‐vis absorbance spectroscopy and cyclic voltammetry (CV) were used to compare the kinetics of the formation of SAMs on gold. Our results suggest that BZIT should have a relatively faster self‐assembly than PHIT, as indicated from signal decrease in the CV graph, which suggests a more vertical stance for BZIT in line with Raman measurements. Copyright © 2006 John Wiley & Sons, Ltd.     

Binding property and structure of aromatic isocyanide self‐assembly monolayers on Ag and Au surfaces

The binding property of p‐biphenyl isocyanide self‐assembled monolayers (SAMs) on Au and Ag was investigated by temperature‐dependent surface‐enhanced Raman spectroscopy (SERS). p‐Biphenyl isocyanide was found to desorb on Ag at a low temperature of ～393 K whereas it appeared to remain enduring at a high temperature of ～453 K for Au. Structures of p‐biphenyl isocyanide SAMs on Au and Ag flat films were checked by means of near‐edge x‐ray absorption fine structure spectroscopy (NEXAFS) at the two different normal (90° ) and grazing (20° ) angles of the incident x‐ray beam. Our results suggested that the SAMs prepared by p‐biphenyl isocyanide should have a relatively disordered structure even at room temperature on both Au and Ag, as indicated from an insubstantial change in NEXAFS spectra at the two different angles from those of p‐biphenyl thiolate and p‐biphenyl methanethiolate. The weakness of the isocyanide–metal bond in comparison with the sulphur–metal bond may result in both low surface coverage and orientational disorder. A density functional theory calculation method was employed to attempt to explain the difference in stability for phenyl isocyanide on Ag and Au surfaces. Our calculation result yielded a lower binding energy of phenyl isocyanide on Ag than that on Au, consistent with the temperature‐dependent Raman results. Copyright © 2005 John Wiley & Sons, Ltd.     

聚乙酰亚胺涂敷单晶硅表面上全氟亏酸单层膜

Ultra-thin film of perfluorodecanoic acid expected to be excellent lubricant for micro-machines was prepared successfully on single crystal silicon substrate.The film was characterized by means of X-ray photoelectron spectroscopy (XPS) and contact-angle meter.The chemical reaction involved in the preparation of the ultra-thin film was discussed as well.After being immersed in a dilute aqueous solution of polyethyleneimine (PEI) for 15 minutes and rinsed with distilled water,the silicon substrate was coated with a thin film of PEI,which was then put into a dilute solution (1× 10－ 3 mol· L－ 1) of perfluorodecanoic acid in hexadecane.Subsequently the steady perfluorodecanoic acid ultra-thin film was developed on PEI coating in the presence of a covalent amide bond between carboxylic group and the primary or secondary amine groups of PEI.This process was accompanied by the contact angle changes of water droplet on the Si surface (see Table 1).Moreover,the reaction between perfluorodecanoic acid and PEI was significantly influenced by N,N′ -dicyclohexylcarbodiimide (DCCD).The contact angle on the ultra-thin film of perfluorodecanoic acid is only 66.3° in the absence of DCCD in the reacting solution; it rises to 89.4° in the presence of DCCD.This indicates that the reaction between perfluorodecanoic acid and PEI was accelerated by DCCD,and the quality of perfluorodecanoic acid ultra-thin film thus improved.XPS analysis of the ultra-thin film indicates that the derivatization of PEI with perfluorodecanoic acid was accompanied by several changes.First,a large and highly symmetrical F 1s peak appeared at 688.3 eV (C－ F*).Secondly,a new peak of N 1s appeared at 400.7 eV (chemical shift 1.4 eV),which was attributed to the N atom attached to the carbonyl group (O=C－ N*).Thirdly,three new peaks of C 1s appeared at 286.1 eV (chemical shift 1.5 eV),288.1 eV (chemical shift 3.5 eV),and 291.0 eV (chemical shift 5.4 eV),respectively.These C 1s peaks were attributed to the C atom attached to the O=C－ N group (O=C－ N－ C*),the carboxyl C atom (O=C*－ N),and the C atom in － CF3 group (C*－ F),respectively.Therefore it can be concluded that perfluorodecanoic acid has been chemically adsorbed onto the surface of PEI and perfluorodecanoic acid ultra-thin film prepared successfully.     

偶氮苯衍生物自组装膜的表征及组装动力学

报导了4-正辛基-4′-（3－巯基丙氧基）偶氮苯（简称C8AzoC3）自组装膜（Self-AssembledMonolnyersSAMs）的表征及其自组装成膜动力学，接触角滴定、原子力显微镜（AFM）及电化学的实验结果表明，C8AzoC3分子在金表面自组装形成致密有序的流水性单分子膜，并且在电极上没有明显的电化学响应．通过控制组装时间，考察了偶氮苯自组装形成单分子膜的动力学过程，从接触角和电化学数据得到组装过程的速率常数kad为（1.2±0.2）×103mol-1·dm3·s－1；依据不同组装时间形成的自组装膜的特征循环伏安行为，提出了C8AzoC3分子在金表面自组装过程的动态模型．     

自组装化学镀银

用三甲氧基巯基丙基硅烷作偶联剂,通过溶剂抽提法获得单分层自组装巯基化 的玻璃。XPS和AES检测了从多层沉积到单分子层形成的过程。将所得的玻璃用于化 学镀银,XPS分析表明,溶液中新生的银通过S-Ag键的形成结合在自组装膜上,银 进一步沉积生成光亮的银镜。对沉积在巯基单分子层自组装后的玻璃上的银层进行 SEM和X射线衍射分析,结果表明用这种方法得到的镀层牢固度优于常规化学镀银所 得银层,晶体结构与常规化学镀银所得层以及金属银的晶体结构一致。     

一种结构新颖的二茂铁硫醇自组装膜的电化学行为

合成二茂铁乙烯基吡啶硫醇(FcC2′PyC4SH,I)及其还原产物二茂铁乙烷基吡啶硫醇(FcC2′PyC4SH,Ⅱ).再利用分子自组装技术在金电极表面形成二茂铁乙烯基吡啶硫醇单分子膜,通过循环伏安法探讨了这种自组装膜与结构相关的电化学响应.     

The different self-assembled way of n- and t-dodecyl mercaptan on the surface of copper

The self-assembled monolayers (SAMs) of n- and t-dodecyl mercaptan on the surface of copper have been obtained. As evidenced by electrochemical impedance spectroscopy (EIS), two kinds of the alkanethiols can self-assemble on the copper surface. But the results of the quartz crystal microbalance (QCM) show that the self-assembled way of the two alkanethiols are different. The SAMs of n-dodecyl mercaptan can increase the weight of the QCM electrode and the SAMs of t-dodecyl mercaptan, on the contrary, make the weight of the QCM electrode decrease. Inspected with the SEM, it is found that a lot of pits spread all over the copper surface after having been modified with t-dodecyl mercaptan. All the results suggest that the self-assemble of t-dodecyl mercaptan on the copper surface can erode and dissolve copper surface sharply.     

一种抗非特异性蛋白质吸附多肽的制备以及性能表征

采用缩聚法制备了聚天冬氨酸(D)带赖氨酸(K)侧链的抗非特异性蛋白质吸附多肽Poly(D)-K.凝胶渗透色谱(GPC)、核磁共振波谱(NMR)及傅里叶变换红外光谱(FTIR)考察目标多肽的分子量和结构;圆二色(CD)光谱仪考察多肽在水溶液中的二级构象;X射线光电子能谱(XPS)考察多肽自组装单分子膜(SAMs)的组成.结果表明,已经制备得到目标多肽,其重均分子量约为3.8×103,多分散系数为1.33,平均聚合度约为12.4;多肽在水溶液中呈无规线团结构;且多肽能通过主链末端的巯基在金片表面自组装成膜.设定组织培养聚苯乙烯(TCPS)表面的蛋白质吸附量为100%,酶联免疫吸附分析法(ELISA)测得该多肽SAMs表面对羊抗人免疫球蛋白(anti-Ig G)和纤维蛋白原(fibrinogen,Fg)的最低相对吸附量分别为(8.5±3.6)%和(12.5±4.8)%.MTT法考察该多肽的体外细胞毒性,5 mg/m L条件下细胞存活率为(87.6±4.2)%.