Green synthesis of rosettelike silver nanocrystals with textured surface topography and highly efficient SERS performances

3D rosettelike silver nanocrystals were synthesized in a large scale via a green synthetic method at room temperature without using any surfactants. The rosettelike silver nanocrystals exhibit a special textured surface morphology with a wedge-shaped architecture and higher specific surface area. The shape, size and surface morphology of the silver nanostructures can be well controlled by changing the reaction parameters. Further investigation shows different surface morphologies of silver lead to different surface plasmon resonance (SPR) and resulting surface-enhanced Raman scattering (SERS) properties. And the rosettelike silver with textured surface morphology displays much higher SERS enhancement ability than hollow sphere silver and stringlike silver, which demonstrates the crucial role of nanoscale surface texturing on the plasmonic response of silver particles. Importantly, the detection limit of rosettelike silver for Rhodamine 6G (R6G) dye can reach up to 10(-14) M, which meets the requirements of ultratrace detection of analytes using SERS.