​Controlling the size, no., and shape of nanogaps in plasmonic nanostructures is of significant importance for the development of novel quantum plasmonic devices and quant. sensing techniques such as surface-enhanced Raman scattering (SERS). Here, the authors introduce a new synthetic method based on coordination interactions and galvanic replacement to prep. core-shell plasmonic nanorods with tunable enclosed nanogaps. Decorating Au nanorods with Raman reporters that strongly coordinate Ag+ ions (e.g., 4-mercaptopyridine) afforded uniform nucleation sites to form a sacrificial Ag shell.