Cheng Lanxia
EaStCHEM and School of Chemistry, University of St. Andrews, St. Andrews KY16 9ST, UK.
Department of Material Sciences and Engineering, University of Texas at Dallas, Richardson, TX 75080, USA.
Materials (Basel). 2016 Dec 16;9(12):1016. doi: 10.3390/ma9121016.
Understanding the adsorption properties of DNA bases on metal surfaces is fundamental for the rational control of surface functionalization leading to the realisation of biocompatible devices for biosensing applications, such as monitoring of particular parameters within bio-organic environments and drug delivery. In this study, the effects of deposition rate and substrate temperature on the adsorption behavior of adenine on Cu(110) surfaces have been investigated using scanning tunneling microscopy (STM) and density functional theory (DFT) modeling, with a focus on the characterization of the morphology of the adsorbed layers. STM results revealed the formation of one-dimensional linear chains and ladder-like chains parallel to the [110] direction, when dosing at a low deposition rate at room temperature, followed by annealing to 490 K. Two mirror related, well-ordered chiral domains oriented at ±55° with respect to the [110] direction are formed upon deposition on a substrate kept at 490 K. The molecular structures observed via STM are rationalized and qualitatively described on the basis of the DFT modeling. The observation of a variety of ad-layer structures influenced by deposition rate and substrate temperature indicates that dynamic processes and hydrogen bonding play an important role in the self-assembly of adenine on the Cu(110) surface.
了解DNA碱基在金属表面的吸附特性，对于合理控制表面功能化从而实现用于生物传感应用的生物相容性设备至关重要，例如监测生物有机环境中的特定参数以及药物递送。在本研究中，使用扫描隧道显微镜（STM）和密度泛函理论（DFT）建模研究了沉积速率和衬底温度对腺嘌呤在Cu(110)表面吸附行为的影响，重点是表征吸附层的形态。STM结果显示，在室温下以低沉积速率进行剂量注入并随后退火至490 K时，会形成与[110]方向平行的一维线性链和梯状链。当沉积在保持在490 K的衬底上时，会形成两个与镜面相关的、排列良好的手性畴，它们相对于[110]方向的取向为±55°。基于DFT建模对通过STM观察到的分子结构进行了合理化和定性描述。观察到受沉积速率和衬底温度影响的各种吸附层结构，表明动态过程和氢键在腺嘌呤在Cu(110)表面的自组装中起重要作用。
