Sevilla Paz, Sánchez-Cortés Santiago, García-Ramos José V, Feis Alessandro
Departamento de Química Física II, Facultad de Farmacia, Universidad Complutense de Madrid , 28040 Madrid, Spain.
J Phys Chem B. 2014 May 15;118(19):5082-92. doi: 10.1021/jp502008a. Epub 2014 May 6.
Gold nanoparticles are being increasingly proposed as biotechnological tools for medical diagnosis and therapy purposes. Their safety for human beings and the environment is therefore becoming an emerging issue, which calls for basic research on the interactions between nanostructured gold particles and biological materials, including physicochemical studies of model systems. In this Article, we focus on the "reaction products" of a widely known nanoparticle type, citrate-capped 30 nm gold nanospheres, with a model protein, horse myoglobin. Protein adsorption and partial denaturation were accompanied by the formation of nanoparticle aggregates with strongly distinct optical spectroscopy properties and shapes, as observed by transmission electron microscopy. We singled out the concentration of myoglobin as the determinant of these differences, and verified on this basis that surface-enhanced Raman scattering (SERS) spectra can only be obtained by aggregates with strong interparticle optical coupling, which are obtained at low protein concentration. The results can be useful both in improving the spectroscopy of biomolecules and in understanding the formation of the protein corona in biomedical applications.
金纳米颗粒作为用于医学诊断和治疗目的的生物技术工具，正越来越多地被提出。因此，它们对人类和环境的安全性正成为一个新出现的问题，这就需要对纳米结构金颗粒与生物材料之间的相互作用进行基础研究，包括对模型系统的物理化学研究。在本文中，我们重点关注一种广为人知的纳米颗粒类型，即柠檬酸盐包覆的30纳米金纳米球与一种模型蛋白——马肌红蛋白的“反应产物”。如通过透射电子显微镜观察到的，蛋白质吸附和部分变性伴随着具有强烈不同光学光谱性质和形状的纳米颗粒聚集体的形成。我们确定肌红蛋白的浓度是这些差异的决定因素，并在此基础上验证了表面增强拉曼散射（SERS）光谱只能由具有强颗粒间光学耦合的聚集体获得，而这种聚集体是在低蛋白浓度下形成的。这些结果对于改善生物分子的光谱学以及理解生物医学应用中蛋白质冠层的形成都可能是有用的。
