title: Large-scale uniform Au nanodisk arrays fabricated via x-ray interference lithography for reproducible and sensitive SERS substrate.
abstract: Large-scale Au nanodisk arrays on Si substrate are successfully fabricated via x-ray interference lithography and followed by electron-beam vapor deposition. The Au nanodisk arrays exhibit a significant, uniform, and reproducible surface enhancement on Raman scattering signal, which enables the detection of R6G as low as 10(-8) M with an enhancement factor of 10(6). Importantly, the Au nanodisk arrays SERS-active substrates with uniformly high sensitivity also have high reproducibility and stability. The diameters of the nanodisks and the inter-disk distance can be simply optimized to obtain high enhancement in Raman signal by varying exposure time and development time in XIL process. The electric fields of the Au nanodisks with various diameters and inter-disk distance simulated by the finite difference time domain (FDTD) techniques further confirm that the Raman signal enhancement of Au nanodisks is determined by the diameters of nanodisks and the inter-disk distance of nanodisks. The Au/Ag double-layer bimetal nanodisk arrays are also fabricated which show a significant increase in the Raman signal enhancement than that of the Au nanodisk arrays. XIL nanofabrication appears to be a feasible approach to prepare uniform and reproducible SERS-active substrates with high sensitivity for practical SERS applications.
authors.affiliation: Soochow University-Western University Centre for Synchrotron Radiation Research, Institute of Functional Nano &#38; Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science &#38; Technology, Soochow University, Suzhou, Jiangsu, 215123, People's Republic of China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Zhang
authors.forename: Shumin
authors.initials: S
authors.lastname: Yang
authors.forename: Liansheng
authors.initials: L
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Zhu
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhong
authors.forename: Xuhui
authors.initials: X
authors.lastname: Sun