First principle study of cysteine molecule on intrinsic and Au-doped graphene surface as a chemosensor device.
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.
Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, People's Republic of China.
Zhuxia
Z
Zhang
Husheng
H
Jia
Fei
F
Ma
Peide
P
Han
Xuguang
X
Liu
Bingshe
B
Xu
D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism*; D004553:Electric Conductivity; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D013499:Surface Properties
D006046:Gold; D006108:Graphite; D003545:Cysteine