Highly selective protein patterning on gold-silicon substrates for biosensor applications
Highly selective protein patterning on gold-silicon substrates for biosensor applications
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DOI：
10.1021/la025529j
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发表时间：
2002-08-20
期刊：
影响因子：
3.9
通讯作者：
Zhang, MQ
中科院分区：
文献类型：
--
作者：
Veiseh, M;Zareie, MH;Zhang, MQ
使用光刻和化学选择性在2D传感器表面上精确地图案化蛋白质。在硅衬底上制作了金正方形的微阵列。用混合的COOH封端的自组装单分子层（SAM）修饰金区域，以具有对所需蛋白质或肽的高亲和力。硅区域通过硅烷化用聚乙二醇（PEG）改性以提供对蛋白质吸附的高电阻率。通过荧光显微镜和原子力显微镜（AFM）观察蛋白质表面覆盖。原子力显微镜也被用于研究蛋白质的形态，以了解蛋白质与自组装膜在分子水平上的相互作用。通过傅里叶变换红外光谱（FTIR）检查固定在自组装膜上的蛋白质和肽。进行表面润湿性的接触角测量以确认表面改性反应的成功。蛋白质电阻的PEG固定在裸硅基板上和在硅区的金图案化的硅基板进行了比较，并发现，后者具有更高的电阻率蛋白质吸附。荧光和高分辨率AFM图像均表明，牛血清白蛋白（BSA）和纤连蛋白分子在图案化基底的金区域上形成了密集的层，而免疫球蛋白（IgG）的覆盖率较低。利用表面等离子体共振（SPR）技术研究了特异性抗原-抗体结合（BSA-抗-BSA），以表征附着在金基底上的抗原的生物活性。表面等离子体共振结果表明，共价结合在金表面的BSA蛋白比物理结合的BSA蛋白具有更好的生物活性。本研究表明，蛋白质或肽，分子结构和固定技术影响的覆盖率，形态和生物活性的附着蛋白质的基板上，这是至关重要的生物传感器的操作行为。
Proteins were precisely patterned on 2D sensor surfaces using photolithography and chemical selectivity. Microarrays of gold squares were fabricated on silicon substrates. The gold regions were modified with mixed COOH-terminated self-assembled monolayers (SAMs) to have a high affinity for the desired proteins or peptides. The silicon regions were modified with polyethylene glycol (PEG) by silanization to provide a high resistivity to Protein adsorption. Protein surface coverage was visualized by fluorescence microscopy and atomic force microscopy (AFM). AFM was also used for studying protein morphology to understand the interaction of proteins with SAMs at the molecular level. Proteins and peptides immobilized on SAMs were examined by Fourier transform infrared (FTIR) spectroscopy. Contact angle measurement for surface wettability Were conducted to confirm the success of the surface modification reactions. Protein resistance by the PEGs immobilized on bare silicon substrates and on the silicon regions of gold-patterned silicon substrates was compared, and it was found that the latter has a higher resistivity to protein adsorption. Both fluorescence and high-resolution AFM images indicated that bovine serum albumin (BSA) and fibronectin molecules formed a densely packed layer on the gold regions of the patterned substrates, while the immunoglobulin's (IgG) coverage was low. Specific antigen-antibody binding (BSA-anti-BSA) was studied using the surface plasmon resonance (SPR) technique for characterizing the bioactivity of the antigen attached to the gold substrates. The SPR results showed that the BSA proteins bound covalently to the gold surfaces have a much better bioactivity than those bound physically. This study suggests that protein or peptide, molecular structures, and the immobilization technique influence the coverage, morphology, and bioactivity of the attached proteins on the substrates which is crucial to the operational behavior of biosensors.