Fig. 5

Multi-step masked nanosynthesis. a Schematics illustrating the multi-step functionalization enabled by the continual contraction of the PSPAA shell. b–g STEM image, EDX mapping, and TEM image of the resulting Pdtip-Agring-(AuNR-1)@PSPAA-Agring-Pdtip, with short b–f and long g exposed segments. The scale bars are 100 nm