Design and One-Pot Synthesis of Capsid-like Gold Colloids with Tunable Surface Roughness and Their Enhanced Sensing and Catalytic Performances

Abstract

Viral capsid-like particles tiled with mosaic patches have attracted great attention as they imitate nature’s design to achieve advanced material properties and functions. Here, we develop a facile one-pot soft-template method to synthesize biomimetic gold capsid-like colloids with tunable particle size and surface roughness. Uniform submicron-to-micron-sized hollow gold colloidal particles are successfully achieved by using tannic acids as soft templates and reducing agents, which first self-assemble into spherical complex templates before the reduction of Au3+ ions via their surface hydroxyl groups. The surface roughness, the size, and the total number of the patches of the prepared gold particles are further tuned, utilizing a mechanism that offers morphology control by varying the number of surface hydroxyl groups participating in the reduction reactions. Among different capsid-like gold colloids, those possessing a rough surface display superior catalytic properties and show promising results as surface-enhanced Raman spectroscopy (SERS) solid substrates for detecting small organic molecules and biomimetic enzymes in a liquid phase for sensing biomolecules in real samples. These capsid-like gold colloids are also expected to find practical applications in delivery systems, electronics, and optics. We believe that our strategy of imitating nature’s design of capsid-like structures should also be used in the design and fabrication of other functional colloidal particles.

Fabrication of Adjustable Au/Carbon Hybrid Nanozymes with Photothermally Enhanced Peroxidase Activity and Ultra-sensitivity for Glutathione Detection

“…Surface roughness was quantified as the standard deviation of the nanoparticle outer diameter and the fitted circle diameter. 17 Both the increased distribution density and size of Au nanoparticles contribute to the increase in surface roughness (Figure S6). It is worth mentioning that the surface roughness of CAu nano-composites has a consistent trend with their hydrophilicity (Figure S7).…”

“…In order to further explore the regulation mechanism of macroscopic hydrophilic and hydrophobic properties of CAu nano-composites, the surface roughness was also analyzed. Surface roughness was quantified as the standard deviation of the nanoparticle outer diameter and the fitted circle diameter . Both the increased distribution density and size of Au nanoparticles contribute to the increase in surface roughness (Figure S6).…”

“…Nanozymes have received more attention, and hence been developed for applications of biological detection, disease treatment, bacterial inhibition, and other fields, since the discovery of Fe 3 O 4 nanozymes in 2007. − Until date, many inorganic nanomaterials such as precious metals, − metal oxides, , carbon materials, , and their hybrid complexes − have been uncovered to display enzyme-like activities including oxidase, peroxidase, catalase, and superoxide dismutase-mimic properties. Among them, Au nanoparticles are one of the most widely studied nanozymes because of their adjustable catalytic performance and synergistic photothermal capability. , However, Au nanoparticles usually have poor dispersibility and stability, which will lead to compromised catalytic activity . Therefore, the preparation of highly dispersed and stable Au nanoparticles has always been a purpose for the preparation of highly catalytic Au nanozymes. − Notably, chemically inert hollow carbon nanospheres (HCNs) can physically promote the dispersity of metallic nanoparticles through their abundant and large cavities. ,, The inner cavity can be used as a nanoreactor, and the mesoporous structure provides a convenient approach for mass transfer during the reaction process, which introduces high catalytic activity. , In addition, both carbon and Au nanoparticles are considered to be excellent photothermal agents.…”

Au Nanoflowers for Catalyzing and In Situ Surface-Enhanced Raman Spectroscopy Monitoring of the Dimerization of p-Aminothiophenol

“…In the presence of the Au NFs prepared at R Au/APTES of 1:8, the signals were enhanced greatly, corresponding to an enhanced factor (EF) of 2 × 10 5 , comparable to performance of most of the anisotropic Au particles in the literature (Table S1). ,− ,− After the addition of H 2 O 2 , a new Raman band at 1430 cm –1 , assigned to ring-stretching vibrations associated with the NN moiety, became observable (Figure a), indicating that the Au NFs are capable of catalyzing the dimerization of p -ATP into DMAB in the presence of H 2 O 2 , via conversion of the amino groups in p -ATP into NN bond induced by • OH generated from the decomposition of H 2 O 2 . ,, In the time-dependent SERS spectra, which were normalized according to the signal of the C–S bond at 1078 cm –1 , the intensity of the signal at 1430 cm –1 , assigned to the NN bond, increased gradually with the reaction time (Figure b), indicating the gradual conversion of p -ATP into DMAB with the proceeded reaction. The intensity ratio of the Raman signals at 1430 and 1078 cm –1 , which may represent the amount of DMAB generated from the dimerization of p -ATP, , increased with the reaction time and reached a platform within 5 min.…”

Critical Review on Synthetic Routes and Catalytic Applications of Hollow Nanomaterials

“…[90] These spheres contain nano-sponge like shell and hollow interior generated by mixing precursor solution of platinum with silica spheres. [91] 0.1 M ascorbic acid added for the complete synthesis of platinum nanoparticles. [92] Nucleation sites results when amino groups interact with Pt nanoparticles and attached to silica surface.…”