Synthesis of coral-shaped gold nanoparticles for SERS sensing applications

This research describes a new method of aqueous synthesis of gold nanoparticles in the presence of cetyltrimethylammonium bromide and folic acid through a seed-mediated growth approach. These nanoparticles have a shape similar to corals, and therefore, we referred to them as 'gold nanocorals' (AuNCs). Specifically, AuNCs consist of a solid core surrounded densely by branches. The branches exhibit nanosized roughness that creates multiple plasmonic hot-spots that increase AuNCs' SERS activity. In this study, we demonstrated that at the fast scanning times necessary for biomedical applications, AuNCs exhibit an analytical enhancement factor greater than 10(3) and 7 times greater enhancement of the Raman signal compared to gold nanostars. AuNCs-based SERS substrates demonstrated a good ability to reproduce signals collected, and thereby confirmed AuNCs feasibility in generating reliable and sensitive SERS substrates.