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.
Zhang
Zhuxia
Z
Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, People's Republic of China.
Jia
Husheng
H
Ma
Fei
F
Han
Peide
P
Liu
Xuguang
X
Xu
Bingshe
B
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