Abstract
Gold nanostars are one of the most fascinating anisotropic nanoparticles. The morphology of a nanostar can be controlled by changing various synthetic parameters; however, the detailed growth mechanism is still not fully understood. Herein, we investigate this process in six-branched nanostars, focusing first on the properties of a single crystalline seed, which evolves to include penta-twinned defects as the gateway to anisotropic growth into the 6-branched morphology. In particular, we report on a high-yield seed-mediated protocol for the synthesis of these particles with high dimensional monodispersity in the presence of Triton-X, ascorbic acid, and AgNO 3 . Detailed spectroscopic and microscopic analyses have allowed the identification of several key intermediates in the growth process, revealing that it proceeds via penta-twinned intermediate seeds. Importantly, we report the first experimental evidence tracking the location of silver with sub-nanometer resolution and prove its role as a stabilizing agent in these highly branched nanostructures. Our results indicate that metallic silver on the spikes stabilizes the nanostar morphology and the remaining silver, present when AgNO 3 is added at a high concentration, deposits on the core and between the bases of neighboring spikes. Importantly, we also demonstrate the possibility of achieving dimensional monodispersity, reproducibility, and tunability in colloidal gold nanostars that are substantially higher than those previously reported, which could be leveraged to carry out holistic computational-experimental studies to understand, predict, and tailor their plasmonic response.
| Original language | English |
|---|---|
| Pages (from-to) | 2946-2958 |
| Number of pages | 13 |
| Journal | Nanoscale |
| Volume | 11 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Feb 14 2019 |
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ASJC Scopus subject areas
- Materials Science(all)
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Understanding the role of AgNO 3 concentration and seed morphology in the achievement of tunable shape control in gold nanostars . / Atta, Supriya; Beetz, Michael; Fabris, Laura.
In: Nanoscale, Vol. 11, No. 6, 14.02.2019, p. 2946-2958.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Understanding the role of AgNO 3 concentration and seed morphology in the achievement of tunable shape control in gold nanostars
AU - Atta, Supriya
AU - Beetz, Michael
AU - Fabris, Laura
PY - 2019/2/14
Y1 - 2019/2/14
N2 - Gold nanostars are one of the most fascinating anisotropic nanoparticles. The morphology of a nanostar can be controlled by changing various synthetic parameters; however, the detailed growth mechanism is still not fully understood. Herein, we investigate this process in six-branched nanostars, focusing first on the properties of a single crystalline seed, which evolves to include penta-twinned defects as the gateway to anisotropic growth into the 6-branched morphology. In particular, we report on a high-yield seed-mediated protocol for the synthesis of these particles with high dimensional monodispersity in the presence of Triton-X, ascorbic acid, and AgNO 3 . Detailed spectroscopic and microscopic analyses have allowed the identification of several key intermediates in the growth process, revealing that it proceeds via penta-twinned intermediate seeds. Importantly, we report the first experimental evidence tracking the location of silver with sub-nanometer resolution and prove its role as a stabilizing agent in these highly branched nanostructures. Our results indicate that metallic silver on the spikes stabilizes the nanostar morphology and the remaining silver, present when AgNO 3 is added at a high concentration, deposits on the core and between the bases of neighboring spikes. Importantly, we also demonstrate the possibility of achieving dimensional monodispersity, reproducibility, and tunability in colloidal gold nanostars that are substantially higher than those previously reported, which could be leveraged to carry out holistic computational-experimental studies to understand, predict, and tailor their plasmonic response.
AB - Gold nanostars are one of the most fascinating anisotropic nanoparticles. The morphology of a nanostar can be controlled by changing various synthetic parameters; however, the detailed growth mechanism is still not fully understood. Herein, we investigate this process in six-branched nanostars, focusing first on the properties of a single crystalline seed, which evolves to include penta-twinned defects as the gateway to anisotropic growth into the 6-branched morphology. In particular, we report on a high-yield seed-mediated protocol for the synthesis of these particles with high dimensional monodispersity in the presence of Triton-X, ascorbic acid, and AgNO 3 . Detailed spectroscopic and microscopic analyses have allowed the identification of several key intermediates in the growth process, revealing that it proceeds via penta-twinned intermediate seeds. Importantly, we report the first experimental evidence tracking the location of silver with sub-nanometer resolution and prove its role as a stabilizing agent in these highly branched nanostructures. Our results indicate that metallic silver on the spikes stabilizes the nanostar morphology and the remaining silver, present when AgNO 3 is added at a high concentration, deposits on the core and between the bases of neighboring spikes. Importantly, we also demonstrate the possibility of achieving dimensional monodispersity, reproducibility, and tunability in colloidal gold nanostars that are substantially higher than those previously reported, which could be leveraged to carry out holistic computational-experimental studies to understand, predict, and tailor their plasmonic response.
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U2 - 10.1039/c8nr07615d
DO - 10.1039/c8nr07615d
M3 - Article
VL - 11
SP - 2946
EP - 2958
JO - Nanoscale
JF - Nanoscale
SN - 2040-3364
IS - 6
ER -