MB and cancer: In this study, a new method was utilized to generate highly monodisperse and uniform GNR@Ag@mSiO2-MB nanostructures with strong NIR absorbance, photothermal conversion efficiency, large surface area, tunable size, dye loading ability, SERS signal, and Raman stability under phototherapy conditions, which were synthesized to develop a multifunctional nanosystem for cancer cell SERS imaging and phototherapy.