Spike Growth on Patterned Gold Nanoparticle Scaffolds.

Jia, Jin; Metzkow, Nadia; Park, Sang-Min; Wu, Yuhao Leo; Sample, Alexander D; Diloknawarit, Bundit; Jung, Insub; Odom, Teri W · Nano Lett · 2023

basic_science · Level V

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Abstract

This work reports a scaffold-templated, bottom-up synthesis of 3D anisotropic nanofeatures on periodic arrays of gold nanoparticles (AuNPs). Our method relies on substrate-bound AuNPs as large seeds with hemispherical shapes and smooth surfaces after the thermal annealing of as-fabricated particles. Spiky features were grown by immersing the patterned AuNPs into a growth solution consisting of a gold salt and Good's buffer; the number and length of spikes could be tuned by changing the solution pH and buffer concentration. Intermediate structures that informed the growth mechanism were characterized as a function of time by correlating the optical properties and spike features. Large-area (cm<sup>2</sup>) spiky AuNP arrays exhibited surface-enhanced Raman spectroscopy enhancement that was associated with increased numbers of high-aspect-ratio spikes formed on the AuNP seeds.