Oligo(ethylene glycol)-terminated monolayers on silicon surfaces and their nanopatterning with a conductive atomic force microscope

Functionalization of silicon substrate surfaces with a stable monolayer for resisting non-specific adsorption of proteins has attracted great interest,since it is directly relevant to the development of miniature,silicon-based biosensors and implantable microdevices,such as silicon-neuron interfaces.This brief review summarizes our contribution to the development of robust monolayers grown by surface hydrosilylation on atomically flat,hydrogen-terminated silicon surfaces.The review also outlines our strateg...     

Remarkably Efficient Photocurrent Generation Based on a [60]Fullerene–Triosmium Cluster/Zn–Porphyrin/Boron–Dipyrrin Triad SAM

A new artificial photosynthetic triad array, a [60]fullerene–triosmium cluster/zinc–porphyrin/boron–dipyrrin complex ( 1 , Os₃C₆₀/ZnP/Bodipy), has been prepared by decarbonylation of Os₃(CO)₈(CN(CH₂)₃Si(OEt)₃)(μ₃‐η²:η²:η²‐C₆₀) ( 6 ) with Me₃NO/MeCN and subsequent reaction with the isocyanide ligand CNZnP/Bodipy ( 5 ) containing zinc porphyrin (ZnP) and boron dipyrrin (Bodipy) moieties. Triad 1 has been characterized by various spectroscopic methods (MS, NMR, IR, UV/Vis, photoluminescence, and transient absorption spectroscopy). The electrochemical properties of 1 in chlorobenzene (CB) have been examined by cyclic voltammetry; the general feature of the cyclic voltammogram of 1 is nine reversible one‐electron redox couples, that is, the sum of those of 5 and 6 . DFT has been applied to study the molecular and electronic structures of 1 . On the basis of fluorescence‐lifetime measurements and transient absorption spectroscopic data, 1 undergoes an efficient energy transfer from Bodipy to ZnP and a fast electron transfer from ZnP to C₆₀; the detailed kinetics involved in both events have been elucidated. The SAM of triad 1 ( 1 /ITO; ITO=indium–tin oxide) has been prepared by immersion of an ITO electrode in a CB solution of 1 and diazabicyclo‐octane (2:1 equiv), and characterized by UV/Vis absorption spectroscopy, water contact angle, X‐ray photoelectron spectroscopy, and cyclic voltammetry. The photoelectrochemical properties of 1 /ITO have been investigated by a standard three‐electrode system in the presence of an ascorbic acid sacrificial electron donor. The quantum yield of the photoelectrochemical cell has been estimated to be 29 % based on the number of photons absorbed by the chromophores. Our triad 1 is unique when compared to previously reported photoinduced electron‐transfer arrays, in that C₆₀ is linked by π bonding with little perturbation of the C₆₀ electron delocalization.     

Langmuir-Hinshelwood 动力学的有效实验条件

 使用 Langmuir-Hinshelwood (L-H) 动力学的学者大部分未注意到该动力学包含了所有吸附物种采用拟稳态假设的隐含条件, 因而他们通常忽视了确认实验条件是否允许采用拟稳态假设. 然而, 对于大部分气固催化反应, 拟稳态假设的成立需基于催化活性位浓度很小的前提. 对于催化活性位浓度高的反应体系, 其覆盖度较高的吸附物种不满足拟稳态假设. 因此, 在这种情况下通过实验测定的动力学常数没有物理意义, 而仅为该实验条件下的数学回归参数. 本文将活性位浓度小于最高反应气浓度的十分之一视为拟稳态假设成立的充分条件, 通过估算发现许多催化剂并不满足该条件.     

Aminealkylthiol and dithiol self-assembly as adhesion promoter between copper substrate and epoxy resin

To improve adhesion between copper and epoxy resin in printed circuit board, a roughness treatment of copper has been widely used. Nevertheless, new adhesion promoters have to be developed to face the miniaturization and sophistication of the electronic device. Self-assembled monolayers have met increasing interest in this field by using them as coupling agent between copper and the epoxy resin.This paper presents the deposition of an epoxy resin on copper modified by amine alkylthiol and dithiol monolayers and highlights the benefit brought by the monolayer in terms of adhesion.The chemical linkage between the amine SAMs and the epoxy function has been proved by the deposition on a short epoxy fragment, the 2-(4-fluorophenoxy-methyl)oxirane. The deposition of an epoxy resin mixed with amine curing agent has then been successfully achieved on amine terminated SAMs. The resulting polymer is homogeneous and well adherent on their surface, while the adhesion is lower on bare copper and not existing on methyl terminated SAMs. The formation of chemical bond Cu-S and N-epoxy is thus essential to increase the adhesion strength between copper and the polymer.     

Synthesis of Benzaldehyde‐Functionalized Glycans: A Novel Approach Towards Glyco‐SAMs as a Tool for Surface Plasmon Resonance Studies

In recent years the interest in tools for investigating carbohydrate–protein (CPI) and carbohydrate‐carbohydrate interactions (CCI) has increased significantly. For the investigation of CPI and CCI, several techniques employing different linking methods are available. Surface plasmon resonance (SPR) imaging is a most appropriate tool for analyzing the formation of self‐assembled monolayers (SAM) of carbohydrate derivatives, which can mimic the glycocalyx. In contrast to the SPR imaging methods used previously to analyze CPI and CCI, the novel approach reported herein allows a facile and rapid synthesis of linker spacers and carbohydrate derivatives and enhances the binding event by controlling the amount and orientation of ligand. For immobilization on biorepulsive amino‐functionalized SPR chips by reductive amination, diverse aldehyde‐functionalized glycan structures (glucose, galactose, mannose, glucosamine, cellobiose, lactose, and lactosamine) have been synthesized in several facile steps that include olefin metathesis. Effective immobilization and the first binding studies are presented for the lectin concanavalin A.