Fig. 2From: A New Smart Surface-Enhanced Raman Scattering Sensor Based on pH-Responsive Polyacryloyl Hydrazine Capped Ag Nanoparticles a HRTEM images and particle size distribution of Ag@PAH NPs. b pH dependence of the hydrodynamic diameter of Ag@PAH NPs. c pH dependence of the UV-vis absorption spectra of Ag@PAH NPsBack to article page