Kinetics‐Controlled Formation of Gold Clusters Using a Quasi‐Biological System

Abstract

By kinetically controlling a biomimetic reduction in a quasi‐biological system (an aqueous solution containing electrolyte, peptide, and coenzyme), water‐soluble, glutathione‐capped Au clusters with a mean diameter of 1.3 nm are successfully synthesized via a new route. Opportunities that facilitate the control of the reaction are created in such a quasi‐biological system. The relatively slow rate of the biomimetic reduction, the pH‐dependent reducibility of the reducing agent, and the favorable structure of the capping molecules conspire together for the realization of a kinetics‐controlled formation of the Au clusters under mild conditions. Compared to existing methods of synthesizing gold clusters by stoichiometrically controlling the molar ratio of the Au atoms and the ligands, our current method is based on slowing down the reduction of the Au precursors in the initial stage by adjusting the activity of the reducing agent in real time, instead of using a strong reducing agent such as NaBH4. This strategy of rationally utilizing biological or biomimetic processes with unique features to provide a beneficial complement to conventional chemical syntheses could open a new way for the sustainable development of nanotechnology.

Heteroatom Doping Promoted Ultrabright and Ultrastable Photoluminescence of Water-Soluble Au/Ag Nanoclusters for Visual and Efficient Drug Delivery to Cancer Cells

“…Meanwhile, the peak at 162.53 eV of S 2p that is assigned to Au/Ag–S bonds demonstrates a significant enhancement after Ag doping (Figure f), indicating an increased composition and stability of Au/Ag–S bonds in the staple motifs of Au/Ag NCs. The dramatic attenuation of the S 2p band for typical unbound sulfur around 165.59 eV and that for oxidized sulfur around 168.05 eV further evidence the strengthened Au/Ag–S binding, which would be favorable to the chemical stability of Au/Ag NCs (Figure f). , In contrast, we can see that a binding energy of 367.55 eV of Ag 3d for Au/Ag NCs is presented on the oxidation side compared with 367.90 eV of Ag (0) (Figure g). This shift indicates that the Ag atoms in Au/Ag NCs are positively charged and might donate electron density to the Au (0) atom in the kernel due to their different electronegativity .…”

Controllable Biosynthesis and Properties of Gold Nanoplates Using Yeast Extract

“…There are still some metabolites with stronger reducibility in the reaction system, such as reductive sugar and sodium citrate, further reducing Au(I) to Au(0). In addition, ionized metabolites with a long chain, such as some phospholipid [ 53 ] and organic acids [ 54 ] can serve as surfactants. With the addition of NaOH, molecules with amino and thiol groups will become anionic and such anions are strongly nucleophilic, hence attacking and reducing Au(III) to form Au(I) coordination complex.…”

Mechanism-Oriented Controllability of Intracellular Quantum Dots Formation: The Role of Glutathione Metabolic Pathway

“…Inspired from these findings, the biosynthetic yield of CdSe QDs has been improved in the homogeneously engineered P GAL1 - GSH1 cells, providing a specific way to direct the cellular metabolism toward CdSe QD formation. This work will facilitate the future development of QD biosynthesis, as well as the design of quasi-biological systems, − which have applied the principle of temporally and spatially coupling the intracellular irrelated biochemical reactions to the in vitro synthesis of nanomaterials.…”