title: Space-confined fabrication of silver nanodendrites and their enhanced SERS activity.
abstract: Here we report a controllable method based on electrodeposition to fabricate Ag nanodendrites (NDs) on a microwell patterned electrode. The microwell patterns on the ITO electrode are fabricated via the microcontact printing technique. By varying the microwell size and electrodeposition time, the morphology of metal deposits on the microwell patterned ITO electrode can be tuned from boulders to dendrites. At the edge of the microwells, the current density was strengthened, which incurs rapid nucleation. The nucleus develops into dendrites because of Mullins-Sekerka instability. However, only boulders were observed at the center of microwells. By reducing the size of the microwells, only NDs were fabricated due to the edge effect. On the basis of understanding the underlying mechanism for dendritic growth in a confined space, our method is used for fabricating other noble metal (Au, Pt) nanodendrites. The controllable synthesis of Au and Pt NDs indicates the universality of this method. Compared with Ag film obtained from electron beam evaporation, the as-prepared Ag NDs exhibit highly enhanced surface-enhanced Raman scattering (SERS) sensitivity when they are used to detect rhodamine 6G (R6G). This approach provides a very controllable, reliable and general way for space-confined fabricating the noble metal nanodendrite arrays which show great promise in catalysis, sensing, biomedicine, electronic and magnetic devices.
authors.affiliation: Research Center for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, China.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Wang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Xu
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Wen
authors.forename: Hongwu
authors.initials: H
authors.lastname: Du
authors.forename: Shutao
authors.initials: S
authors.lastname: Wang
authors.forename: Xueji
authors.initials: X
authors.lastname: Zhang
mesh_terms: D020811:Biomedical Technology / Q000379:methods; D002384:Catalysis; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010984:Platinum / Q000737:chemistry*; D012235:Rhodamines / Q000032:analysis / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: D012235:Rhodamines; C026188:rhodamine 6G; D012834:Silver; D010984:Platinum; D006046:Gold