Hughes Zak E, Walsh Tiffany R
Institute for Frontier Materials, Deakin University, Geelong VIC 3216, Australia.
Phys Chem Chem Phys. 2016 Jul 14;18(26):17525-33. doi: 10.1039/c6cp02323a. Epub 2016 Jun 15.
The operation of many nanostructured biomolecular sensors and catalysts critically hinges on the manipulation of non-covalent adsorption of biomolecules on unfunctionalised noble-metal nanoparticles (NMNPs). Molecular-level structural details of the aqueous biomolecule/NMNP interface are pivotal to the successful realisation of these technologies, but such experimental data are currently scarce and challenging to obtain. Molecular simulations can generate these details, but are limited by the assumption of non-preferential adsorption to NMNP features. Here, via first principles calculations using a vdW-DF functional, and based on nanoscale sized NMNPs, we demonstrate that adsorption preferences to NP features vary with adsorbate chemistry. These results show a clear distinction between hydrocarbons, that prefer adsorption to facets over edges/vertices, over heteroatomic molecules that favour adsorption onto vertices over facets. Our data indicate the inability of widely used force-fields to correctly capture the adsorption of biomolecules onto NMNP surfaces under aqueous conditions. Our findings introduce a rational basis for the development of new force-fields that will reliably capture these phenomena.
许多纳米结构生物分子传感器和催化剂的运行关键取决于生物分子在未功能化贵金属纳米颗粒（NMNP）上的非共价吸附的操控。水性生物分子/NMNP界面的分子水平结构细节对于这些技术的成功实现至关重要，但目前此类实验数据稀缺且获取具有挑战性。分子模拟可以生成这些细节，但受限于对NMNP特征非优先吸附的假设。在此，通过使用vdW-DF泛函的第一性原理计算，并基于纳米级尺寸的NMNP，我们证明了对NP特征的吸附偏好随吸附质化学性质而变化。这些结果清楚地表明了烃类（优先吸附在晶面上而非边缘/顶点）与杂原子分子（更倾向于吸附在顶点而非晶面上）之间的区别。我们的数据表明，广泛使用的力场无法在水性条件下正确捕捉生物分子在NMNP表面的吸附。我们的发现为开发能够可靠捕捉这些现象的新力场引入了合理依据。
