title: Reusable three-dimensional nanostructured substrates for surface-enhanced Raman scattering.
abstract: To date, fabricating three-dimensional (3D) nanostructured substrate with small nanogap was a laborious challenge by conventional fabrication techniques. In this article, we address a simple, low-cost, large-area, and spatially controllable method to fabricate 3D nanostructures, involving hemisphere, hemiellipsoid, and pyramidal pits based on nanosphere lithography (NSL). These 3D nanostructures were used as surface-enhanced Raman scattering (SERS) substrates of single Rhodamine 6G (R6G) molecule. The average SERS enhancement factor achieved up to 1011. The inevitably negative influence of the adhesion-promoting intermediate layer of Cr or Ti was resolved by using such kind of 3D nanostructures. The nanostructured quartz substrate is a free platform as a SERS substrate and is nondestructive when altering with different metal films and is recyclable, which avoids the laborious and complicated fabricating procedures.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Physics & Tsinghua-Foxconn Nanotechnology Research Center, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China. QunqLi@mail.tsinghua.edu.cn.
authors.forename: Qunqing
authors.initials: Q
authors.lastname: Li
authors.forename: Benfeng
authors.initials: B
authors.lastname: Bai
authors.forename: Shoushan
authors.initials: S
authors.lastname: Fan