Droplet-Confined Electroless Deposition of Silver Nanoparticles on Ordered Superhydrophobic Structures for High Uniform SERS Measurements.

Surface-enhanced Raman scattering spectroscopy (SERS) is a nondestructive testing technique. To increase reproducibility of the SERS measurement is the key issue for improving the performance of SERS. In this article, we demonstrate an efficient method to improve the reproducibility, using confined silver nanoparticles (AgNPs) as a substrate. The AgNPs are formed uniformly on the tops of the prepared nanopillars by droplet-confined electroless deposition on the hydrophobic Si nanopillar arrays. The AgNPs present an excellent reproducibility in Raman measurement; the relative standard deviation is down to 3.40%. There exists a great linear correlation between the concentration of Rhodamine 6G (R6G) and the Raman intensity in the log-log plot; R is 0.998, indicating that this SERS substrate can be applied for the quantitative SERS analysis. Meanwhile, the minimum detection concentration is down to 10 M on the hydrophobic substrate, with R6G as a probe molecule.