Synthesis of starch-based plasmonic core-shell microparticles for SERS applications

Abstract

Here, we report a simple and green approach for the fabrication of gold-shelled starch microbeads (Au-shelled SMBs) that exhibit a significant broadband absorption. We employed SMBs as a soft template to induce the jamming of precoated Au seeds on the surface of SMBs. The resulting Au-shelled SMBs were shown as highly monodisperse spherical particles whose diameter could be controlled from 0.2 μm to 1 μm by modulating the concentration of gold seed. The potential of the core？shell plasmonic materials developed in this study for the SERS-based analytical system was investigated by using a model SERS probe: 4-mercaptobenzoic acid. With the low-cost, renewable, and abundant nature of starch, we believe that this approach would provide an effective means of large-scale production of size-controllable core？shell plasmonic particles exhibiting unique optical properties and excellent SERS activity, which could readily be applied to a range of highly sensitive analytical systems.