Synthesis of sea urchin-shaped Au nanocrystals by double-strand diblock oligonucleotides for surface-enhanced Raman scattering and catalytic application

Abstract

It is of great significance to construct specially designed gold nanocrystals (AuNCs) with precisely controllable size and morphology to achieve an excellent physicochemical performance. In this work, sea urchin-shaped AuNCs with tunable plasmonic property were successfully synthesized by the hybridized double-strand poly adenine (dsPolyA) DNA-directed self-assembly technique. Hybridized dsPolyA as the directing template had suitable rigidity and upright conformation, which benefited the controllable formation of these anisotropic multi-branched AuNCs with the assistance of surfactant. The effects of essential conditions influencing the synthesis and precise morphology control were investigated in detail. COMSOL simulation was used to evaluate their electromagnetic field distribution according to their morphologies, and the result suggested that sea urchin-shaped AuNCs had abundant ‘hot spots’ for surface-enhanced Raman scattering (SERS) detection due to their regular nanoprotuberance structure. Finally, sea urchin-shaped AuNCs with excellent SERS and catalytic performance were applied for the quantitative analysis of food colorant and catalytic degradation of potential pollutants. The SERS enhancement factor of sea urchin-shaped AuNCs was up to 5.27 × 106, and the catalytic degradation rate for 4-NP by these AuNCs was up to −0.13min−1.

DNA-Guided Metallization of Nanomaterials and Their Biomedical Applications

“…Potential DNA templates have different secondary structures, such as single-stranded (ss), double-stranded (ds), hairpin (hp), and triple-junction arms (ta). Researchers have successfully synthesized several shapes of DNA-directed nanostructures, including nanoflowers, nanopolygons, nanocaps with nanobridges, and sea cucumber-like structures [53]. Some examples related to these structures are listed in Table 1.…”

“…Thus, the relatively limited control of nanoseed growth does not allow 100% control of the morphology of the resulting AuNC structures [66]. Gao et al [53] successfully synthesized sea urchin-like AuNCs with tunable plasmonic properties using a self-assembly technique of hybridized double-stranded polyadenine (dsPolyA) DNA (Figure 3B). The hybridized dsPolyA serves as a guide template with suitable rigidity and upright conformation, facilitating the formation of anisotropic multi-branched gold nanocrystals with the assistance of surfactants.…”

Facile Synthesis of Urchin-like Hollow Au Crystals for In Situ SERS Monitoring of Photocatalytic Reaction

“…Guillermo used femtosecond laser shaping to prepare Au nanorods with super-arrow surface plasma resonance (SPR) [12]. Various noble metal nanocrystals with regular morphology have also been prepared one after another, including low-index Crystals 2022, 12, 884 2 of 10 facet crystals [13][14][15][16][17], high-index facet crystals [18][19][20][21][22], flower-like crystals [23][24][25], chiral structure [26][27][28][29], porous structure crystals [30][31][32] and urchin-like crystals [33][34][35].…”