Using Good's Buffers to Control the Anisotropic Structure and Optical Properties of Spiky Gold Nanoparticles for Refractive Index Sensing

Spiky gold nanoparticles show structure-tunable optical properties. Most synthetic procedures, however, cannot independently manipulate the overall particle shape, core size, and spike features. Furthermore, conventional protocols rely on cytotoxic and/or strongly bound surfactants that limit applications. This paper reports a set of parameters to manipulate the anisotropic features of spiky gold nanoparticles grown by using different biocompatible Good's buffers through a seed-mediated synthesis. Spike dimensions were preserved even when large seeds (up to 100 nm) were used. Finally, we obtained particles with high sensitivity to changes in the refractive index of the surroundings by tuning the spike length and width.