Fig. 6

A SEM image of the ZnO/Ti₃C₂T_x substrate. B Spatial map of the SERS intensity (at 1360 cm⁻¹) of 10⁻⁶ M R6G drop-cast on ZnO/Ti₃C₂T_x (n = 16 × 18). C SEM images of Au nanoparticles distributed on the ZnO/Ti₃C₂T_x substrate, inset provides the enlarged image of selected section. D The SERS intensity distribution of the 1360 cm⁻¹ peak across all mapping sites in panel b. E SERS spectra of 10⁻⁴ to 10⁻⁶ M microRNA on ZnO/Ti₃C₂T_x. F Linear fit plots of peaks of 925 cm⁻¹ and 1040 cm.⁻¹, respectively (n = 9)