本文报告了四种蛋白质 - 纤维蛋白原、溶菌酶、丙酮酸激酶和 RNA 酶 A 对金上自组装单层 (SAM) 的吸附研究。所检查的 SAM 源自结构为 HS(CH 2 ) 10 R 的硫醇,其中 R 是 CH 3 、CH 2 OH 和低聚(环氧乙烷)。含有足够大摩尔分数的链烷烃硫醇基团终止于低聚(环氧乙烷)链的单层抵抗所有四种蛋白质的动力学不可逆、非特异性吸附。较长的低聚(环氧乙烷)链在单层中的较低摩尔分数下具有抗性。对蛋白质吸附的抵抗力随着低聚(环氧乙烷)链的长度而增加:阻止吸附的链的最小摩尔分数与 n -0.4 成正比,其中 n 表示每条链的环氧乙烷单元数
本文报告了四种蛋白质 - 纤维蛋白原、溶菌酶、丙酮酸激酶和 RNA 酶 A 对金上自组装单层 (SAM) 的吸附研究。所检查的 SAM 源自结构为 HS(CH 2 ) 10 R 的硫醇,其中 R 是 CH 3 、CH 2 OH 和低聚(环氧乙烷)。含有足够大摩尔分数的链烷烃硫醇基团终止于低聚(环氧乙烷)链的单层抵抗所有四种蛋白质的动力学不可逆、非特异性吸附。较长的低聚(环氧乙烷)链在单层中的较低摩尔分数下具有抗性。对蛋白质吸附的抵抗力随着低聚(环氧乙烷)链的长度而增加:阻止吸附的链的最小摩尔分数与 n -0.4 成正比,其中 n 表示每条链的环氧乙烷单元数
Factors that Determine the Protein Resistance of Oligoether Self-Assembled Monolayers − Internal Hydrophilicity, Terminal Hydrophilicity, and Lateral Packing Density
Protein resistance of oligoether self-assembled monolayers (SAMS) on gold and silver surfaces has been investigated systematically to elucidate structural factors that determine whether a SAM will be able to resist protein adsorption. Oligo(ethylene glycol) (OEG)-, oligo(propylene glycol)-, and oligo(trimethylene glycol)-terminated alkanethiols with different chain lengths and alkyl termination were synthesized as monolayer constituents. The packing density and chemical composition of the SAMS were examined by XPS spectroscopy; the terminal hydrophilicity was characterized by contact angle measurements. IRRAS spectroscopy gave information about the chain conformation of specific monolayers; the amount of adsorbed protein as compared to alkanethiol monolayers was determined by ellipsometry. We found several factors that in combination or by themselves suppress the protein resistance of oligoether monolayers. Monolayers with a hydrophobic interior, such as those containing oligo(propylene glycol), show no protein resistance. The lateral compression of oligo(ethylene glycol) monolayers on silver generates more highly ordered monolayers and may cause decreased protein resistance, but does not necessarily lead to an all-trans chain conformation of the OEG moieties. Water contact angles higher than 70degrees on gold or 65degrees on silver reduce full protein resistance. We conclude that both internal and terminal hydrophilicity favor the protein resistance of an oligoether monolayer. It is suggested that the penetration of water molecules in the interior of the SAM is a necessary prerequisite for protein resistance. We discuss and summarize the various factors which are critical for the functionality of "inert" organic films.