Synergistically controlled nano-templated growth of tunable gold bud-to-blossom nanostructures: a pragmatic growth mechanism

Abstract

A novel nano-templating method with a unique nanocrystal growth mechanism has been introduced for the single-pot production of variable-size (110–360 nm), intrinsically monodispersed, single-shaped, tunable plasmonic (580–1300 nm) gold nanomaterials showing a man-made replica of nature's bud-to-blossom steps associated with the gigantic SERS activity. In the first growth step, we synthesized 45 ± 3 nm gold nano-popcorns (GNPops) from 4.3 ± 1.4 nm spherical gold nano-seeds, and in the second growth step, we used GNPops as templates for controlled overgrowth and to produce bigger gold nano-flowers (GNFs) simply by controlling the viscosity of the surfactant. TEM-based electron tomography (ET) of highly structured GNFs provides their actual morphology with no Bragg diffraction artefacts. Due to their broad plasmon tunability throughout the Vis-NIR region and extraordinarily high Raman activity, these materials are suitable for applications in tunable Plasmon spectroscopy, high-throughput Raman sensing and efficient photothermal therapy in the biological window.