Rapid Fabrication of Homogeneous Submicron Silver Particles via a Microfluidic Chip and Use as a SERS Detection Substrate
Junjie Chen, Suyang Li, Fuqi Yao, Wanbing Xu, Yunfeng Li, Qiang Chen, Pei Liang
Abstract
Silver particles have been widely used in SERS detection as an enhancement substrate. The large-scale synthesis of Ag particles with controllable size and shape is still a challenge. We demonstrate a high-throughput method for the preparation of monodisperse submicron silver particles using S-shaped microfluidic chips. Submicron silver particles were prepared by a simplified reduction method. By adjusting the concentration of the reducing agent ascorbic acid and the stabilizer PVP, the particle size and morphology could be controlled, obtaining a size distribution of 1–1.2 μm for flower-like silver particles and a size distribution of 0.5–0.7 μm for quasi-spherical silver particles. This microfluidic system can be used to fabricate submicron silver particles on a large scale, continuously and stably, with a production efficiency of around 1.73 mg/min. The synthesized submicron silver particles could realize ultra-sensitive SERS detection, and the lowest concentration of rhodamine 6G (R6G) that could be detected was 10−9 M.