Facile synthesis of hydrangea flower-like hierarchical gold nanostructures with tunable surface topographies for single-particle surface-enhanced Raman scattering

Abstract

The physicochemical properties of noble metal nanocrystals depend strongly on their size and shape, and it is becoming clear that the design and facile synthesis of particular nanostructures with tailored shape and size is especially important. Herein a novel class of hydrangea flower-like hierarchical gold nanostructures with tunable surface topographies and optical properties are prepared for the first time by a facile, one-pot, seedless synthesis using ascorbic acid (AA) to reduce hydrogen tetrachloroaurate (HAuCl4) in the presence of (1-hexadecyl)trimethylammonium chloride (CTAC). The morphologies of the synthesized gold nanoflowers are controlled and fine-tuned by varying the synthetic conditions such as the concentration of reagents and the growth temperature. Due to their unique hierarchical three-dimensional (3D) structures with rich hot spots, these gold nanoflowers exhibit an efficient performance in single-particle surface-enhanced Raman scattering (SERS). The work stands out as an interesting approach for anisotropic particle synthesis and morphological control, and the proposed novel, hierarchical gold nanoflowers have a number of exciting potential applications in SERS-based sensors.

Bovine serum albumin assisted preparation of ultra-stable gold nanoflowers and their selective Raman response to charged dyes

“…4a). 10 It is identied the intensity ratios of the (200) and (111) planes, I (200) /I (111) , were 0.39 and 0.23 respectively for the particles prepared at 1.0 and 3.0 mM BSA, suggesting the (111) is the predominant lattice plane to direct the growth of Au nanoowers. 11 Enlarged TEM image indicated that the surface of the Au particle prepared with 1.0 mM BSA was quite smooth (Fig.…”

“…[6][7][8] A general strategy to synthesize Au NFs is to carry out the growth of Au nanoparticles (NPs) in the presence of shape-directing agents, which can preferentially adsorb onto specic crystal planes and thus direct the anisotropic growth of NPs along the uncapped facets. A variety of agents, such as surfactants, 9,10 polymers, 11 and biomolecules with active groups that allow their anchoring onto the specic planes, 12 have been proven to be effective to direct the growth of Au NFs. However, it is documented that Au NFs are readily to go ripening and become spherical in shape, especially in presence of chloride ions and/or under acidic pH.…”

Facile synthesis of flower-like platinum nanostructures as an efficient electrocatalyst for methanol electro-oxidation

“…The effects of reaction conditions, such as growth temperature, precursor, and surfactant, were comprehensively studied to illustrate the growth mechanism of noble metals [30]. We investigated the influence of etching time on GNF to understand the 8 formation of flower-like Pt nanostructures.…”

Synthesis of magnetic core-branched Au shell nanostructures and their application in cancer-related miRNA detection via SERS

“…However, few studies have been conducted specifically on the preparation of highly SERS-active gold shell on the magnetic nanoparticles [24][25][26][27][28], and mainly partially gold coated rough shell or fully coated smooth shell have been prepared for SERS-based detections, which limits the application of MNPs@Au in the field of SERS. According to the SERS mechanism rough surface with nanoscale gaps or tips can generate stronger localized surface plasmon resonance (LSPR) compared with the smooth ones [29][30][31]. Though many gold nanoparticles with branched tips, such as tadpole- [32], star- [33], and urchin-shaped [34], were synthesized with enhanced SERS activities, few researches have been carried on the growth of branched gold shell on the magnetic cores with improved SERS performance.…”