Yin Yuefeng, Cervenka Jiri, Medhekar Nikhil V
Department of Materials Science and Engineering, Monash University , Wellington Road, Clayton, Victoria 3800, Australia.
Department of Thin Films and Nanostructures, Institute of Physics ASCR, v. v. i. , Prague 182 21, Czech Republic.
J Phys Chem Lett. 2017 Jul 6;8(13):3087-3094. doi: 10.1021/acs.jpclett.7b01283. Epub 2017 Jun 22.
The emergence of graphene in recent years provides exciting avenues for achieving fast, reliable DNA/RNA sensing and sequencing. Here we explore the possibility of enhancing electronic fingerprints of nucleobases adsorbed on graphene by tuning the surface coverage and modifying molecular dipoles using first-principles calculations. We demonstrate that intermolecular interactions have a strong influence on the adsorption geometry and the electronic structure of the nucleobases, resulting in tilted configurations and a considerable modification of their electronic fingerprints in graphene. Our analysis reveals that the molecular dipole of the nucleobase molecules plays a dominant role in the electronic structure of graphene-nucleobase systems, inducing significant changes in the work functions and energy level alignments at the interface. These results highlight tunable control of the measured molecular signals in graphene by optimizing the surface contact between nucleobases and graphene. Our findings have important implications for identification and understanding of molecular fingerprints of DNA/RNA nucleobases in graphene-based sensing and sequencing methods.
近年来石墨烯的出现为实现快速、可靠的DNA/RNA传感和测序提供了令人兴奋的途径。在此，我们通过第一性原理计算，探索了通过调节表面覆盖率和修饰分子偶极来增强吸附在石墨烯上的核碱基电子指纹的可能性。我们证明分子间相互作用对核碱基的吸附几何结构和电子结构有强烈影响，导致倾斜构型，并使其在石墨烯中的电子指纹发生相当大的改变。我们的分析表明，核碱基分子的分子偶极在石墨烯-核碱基系统的电子结构中起主导作用，在界面处引起功函数和能级排列的显著变化。这些结果突出了通过优化核碱基与石墨烯之间的表面接触来对石墨烯中测量的分子信号进行可调控制。我们的发现对于基于石墨烯的传感和测序方法中DNA/RNA核碱基分子指纹的识别和理解具有重要意义。
