Dihydroxyphenylalanine (DOPA) is extensively reported to be a surface-independent anchor molecule in bioadhesive surface modification and antifouling biomaterial fabrication. However, the mechanisms of DOPA adsorption on versatile substrates and the comparison between experimental results and theoretical results are less addressed. We report the adsorption of DOPA anchored monomethoxy poly(ethylene glycol) (DOPA-mPEG) on substrates and surface wettability as well as antifouling property in comparison with thiol and hydroxyl anchored mPEG (mPEG-SH and mPEG-OH). Gold and hydroxylated silicon were used as model substrates to study the adsorptions of mPEGs. The experimental results showed that the DOPA-mPEG showed higher affinity to both gold and silicon wafers, and the DOPA-mPEG modified surfaces had higher resistance to protein adsorption than those of mPEG-SH and mPEG-OH. It is revealed that the surface wettability is primary for surface fouling, while polymer flexibility is the secondary parameter. We present ab initio calculations of the adsorption of mEGs with different end-functionalities on Au and hydroxylated silicon wafer (Si-OH), where the binding energies are obtained. It is established that monomethoxy ethylene glycol (mEG) with DOPA terminal DOPA-mEG is clearly favored for the adsorption with both gold and Si-OH surfaces due to the bidentate Au—O interactions and the bidentate O—H bond interactions, in agreement with experimental evidence.

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具有不同末端接枝基团的聚（乙二醇）表面改性：实验和理论研究

据报道，二羟基苯丙氨酸 (DOPA) 是一种表面独立的锚定分子，用于生物粘附表面改性和防污生物材料制造。然而，多巴在多功能基材上的吸附机制以及实验结果与理论结果之间的比较很少被提及。我们报告了与硫醇和羟基锚定的 mPEG（mPEG-SH 和 mPEG-OH）相比，多巴锚定的单甲氧基聚（乙二醇）（多巴-mPEG）在基材上的吸附和表面润湿性以及防污性能。金和羟基化硅被用作模型底物来研究 mPEG 的吸附。实验结果表明 DOPA-mPEG 对金和硅片均表现出较高的亲和力，DOPA-mPEG 修饰的表面比 mPEG-SH 和 mPEG-OH 具有更高的抗蛋白质吸附能力。结果表明，表面润湿性是表面污染的主要因素，而聚合物柔韧性是次要参数。我们提出从头计算具有不同末端官能团的 mEG 在 Au 和羟基化硅片 (Si-OH) 上的吸附，其中获得了结合能。已经确定，由于双齿 Au-O 相互作用和双齿 O-H 键相互作用，具有 DOPA 末端 DOPA-mEG 的单甲氧基乙二醇 (mEG) 显然有利于与金和 Si-OH 表面的吸附，与实验证据。