Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, People's Republic of China.
J Mol Model. 2011 Apr;17(4):649-55. doi: 10.1007/s00894-010-0760-2. Epub 2010 Jun 5.
To search for a high sensitivity sensor for cysteine, we investigated the adsorption of cysteine on intrinsic and Au-doped graphene sheets using density functional theory calculations. Binding energy is primarily determined by the type of atom which is closer to the adsorbed sheet. Compared with intrinsic graphene, Au-doped graphene system has higher binding energy value and shorter connecting distance, in which strong Au-S, Au-N and Au-O chemical bond interaction play the key role for stability. Furthermore, the density of states results show orbital hybridization between cysteine and Au-doped graphene sheet, but slight hybridization between the cysteine molecule and intrinsic graphene sheet. Large charge transfers exist in Au-doped graphene-cysteine system. The results of DOS and charge transfer calculations suppose that the electronic properties of graphene can be tuned by the adsorption site of cysteine. Therefore, graphene and Au-doped graphene system both possess sensing ability, except that Au-doped graphene is a better sensor for cysteine than intrinsic graphene.
为了寻找对半胱氨酸具有高灵敏度的传感器，我们使用密度泛函理论计算研究了半胱氨酸在本征和 Au 掺杂石墨烯片上的吸附。结合能主要由更接近吸附片的原子类型决定。与本征石墨烯相比，Au 掺杂石墨烯体系具有更高的结合能值和更短的连接距离，其中强的 Au-S、Au-N 和 Au-O 化学键相互作用对稳定性起着关键作用。此外，态密度结果表明半胱氨酸与 Au 掺杂石墨烯片之间存在轨道杂化，但半胱氨酸分子与本征石墨烯片之间的杂化程度很小。Au 掺杂石墨烯-半胱氨酸体系中存在大量的电荷转移。DOS 和电荷转移计算的结果表明，石墨烯的电子性质可以通过半胱氨酸的吸附位置进行调节。因此，石墨烯和 Au 掺杂石墨烯体系都具有传感能力，只是 Au 掺杂石墨烯比本征石墨烯对半胱氨酸具有更好的传感能力。
