Formation of Silica-Lysozyme Composites Through Co-Precipitation and Adsorption
Formation of Silica-Lysozyme Composites Through Co-Precipitation and Adsorption
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DOI：
10.3389/fmats.2018.00019
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发表时间：
2018-04
影响因子：
3.2
通讯作者：
Daniela B. van den Heuvel;T. Stawski;D. Tobler;R. Wirth;C. Peacock;L. Benning
中科院分区：
文献类型：
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作者：
Daniela B. van den Heuvel;T. Stawski;D. Tobler;R. Wirth;C. Peacock;L. Benning
二氧化硅和蛋白质之间的相互作用对于生物二氧化硅的形成和新型功能杂化材料的生产至关重要，适用于一系列工业应用。蛋白质控制了沉淀途径和所得硅有机复合材料的性质。在这里，我们展示了通过两种不同的合成方法（共沉淀法和吸附法）形成二氧化硅-溶菌酶复合材料的数据，并表明，当使用基于同步加速器的散射（全散射和SAXS）、光谱、电子显微镜和电位法的组合分析时，这些复合材料的化学和结构特性差异很大。我们记录到，虽然溶菌酶没有被纳入二氧化硅的分子结构中，也没有改变它的存在，但由于静电和潜在的疏水相互作用，它强烈增强了二氧化硅颗粒的聚集，导致形成与纯二氧化硅不同的复合材料。两种合成方法的差异随溶菌酶含量的增加而增大。然而，两组复合材料之间的绝对变化存在很大差异，因为溶菌酶不仅影响共沉淀过程中的聚集，还影响共沉淀过程中的颗粒生长和可能的聚合。我们的研究结果提高了对有机大分子如何与溶解二氧化硅和纳米二氧化硅相互作用的基本理解，以及这些相互作用如何控制硅酸钠溶液（一种广泛可用且廉价的起始材料）中二氧化硅-有机复合材料的形成途径。
Interactions between silica and proteins are crucial for the formation of biosilica and the production of novel functional hybrid materials for a range of industrial applications. The proteins control both precipitation pathway and the properties of the resulting silica-organic composites. Here we present data on the formation of silica-lysozyme composites through two different synthesis approaches (co-precipitation vs. adsorption) and show that the chemical and structural properties of these composites, when analyzed using a combination of synchrotron-based scattering (total scattering and SAXS), spectroscopic, electron microscopy and potentiometric methods vary dramatically. We document that while lysozyme was not incorporated into nor did its presence alter the molecular structure of silica, it strongly enhanced the aggregation of silica particles due to electrostatic and potentially hydrophobic interactions, leading to the formation of composites with characteristics differing from pure silica. The differences increased with increasing lysozyme content for both synthesis approaches. Yet, the absolute changes differ substantially between the two sets of composites, as lysozyme did not just affect aggregation during co-precipitation but also particle growth and likely polymerization during co-precipitation. Our results improve the fundamental understanding of how organic macromolecules interact with dissolved and nanoparticulate silica and how these interactions control the formation pathway of silica-organic composites from sodium silicate solutions, a widely available and cheap starting material.