Fast tailoring of gold nanoflowers by an interface-modified reverse microdroplet strategy

Gold nanoflowers (Au NFs) have received great attention for surface-enhanced Raman scattering (SERS) applications, due to the high surface area, availability of conjugation sites on surface and the localized surface plasmon resonance . However, their further application is much hampered by the complicated and time-consuming synthesis process, which remains better responded. Herein, we propose a novel & straightforward interface-modified reverse microdroplet strategy to configure homogeneously dispersed Au NFs within two hours, where Au 3+ was reduced by excess aniline as two-in-one medium of reductant and solvent. It is demonstrated that the reaction system is robustly directed by the dynamic built-in reaction interface, thanks to the capping effect of the in-situ formed polyaniline (PANI) and polyvinyl pyrrolidone (PVP). It is further identified that the final morphology of Au NFs is strongly determined by the nucleation & growth rates. Consequently, such a well-tailored microstructure endows the Au NFs with sound performance for SERS applications. When using methylene blue (MB) as a molecular probe , a high SERS enhancement factor above 10 5 is delivered. This work provides a feasible interface-assisted methodology to investigate multi-level structures, and sheds light toward simply advancing versatile nanomaterials for broad applications.