Control over orientation and conformation of surface-immobilized proteins, determining their biological activity, plays a critical role in biointerface engineering. Specific protein state can be achieved with adjusted surface preparation and immobilization conditions through different types of protein-surface and protein-protein interactions, as outlined in this work. Time-of-flight secondary ion mass spectroscopy, combining surface sensitivity with excellent chemical specificity enhanced by multivariate data analysis, is the most suited surface analysis method to provide information about protein state. This work highlights recent applications of the multivariate principal component analysis of TOF-SIMS spectra to trace orientation and conformation changes of various proteins (antibody, bovine serum albumin, and streptavidin) immobilized by adsorption, specific binding, and covalent attachment on different surfaces, including self-assembled monolayers on silicon, solution-deposited polythiophenes, and thermo-responsive polymer brushes. Multivariate TOF-SIMS results correlate well with AFM data and binding assays for antibody-antigen and streptavidin-biotin recognition. Additionally, several novel extensions of the multivariate TOF-SIMS method are discussed. Graphical abstract

中文翻译：

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控制硅烷单层、共轭聚合物和热响应聚合物刷上蛋白质的取向、构象和生物识别：使用 TOF-SIMS 和主成分分析进行研究

控制表面固定化蛋白质的方向和构象，确定其生物活性，在生物界面工程中起着关键作用。如本工作所述，可以通过不同类型的蛋白质-表面和蛋白质-蛋白质相互作用，通过调整表面制备和固定条件来实现特定的蛋白质状态。飞行时间二次离子质谱将表面灵敏度与通过多元数据分析增强的优异化学特异性相结合，是最适合提供蛋白质状态信息的表面分析方法。这项工作突出了 TOF-SIMS 光谱的多变量主成分分析在追踪各种蛋白质（抗体、牛血清白蛋白、和链霉亲和素）通过吸附、特异性结合和共价连接固定在不同表面上，包括硅上的自组装单层、溶液沉积的聚噻吩和热响应聚合物刷。多变量 TOF-SIMS 结果与 AFM 数据和抗体-抗原和链霉亲和素-生物素识别的结合测定密切相关。此外，还讨论了多元 TOF-SIMS 方法的几个新扩展。图形概要 讨论了多元 TOF-SIMS 方法的几个新扩展。图形概要 讨论了多元 TOF-SIMS 方法的几个新扩展。图形概要