On the Effect of Modified Carbohydrates on the Size and Shape of Gold and Silver Nanostructures

Abstract

Gold (Au) and silver (Ag) nanostructures have widespread utilization from biomedicine to materials science. Therefore, their synthesis with control of their morphology and surface chemistry have been among the hot topics over the last decades. Here, we introduce a new approach relying on sugar derivatives that work as reducing, stabilizing, and capping agents in the synthesis of Au and Ag nanostructures. These sugar derivatives are utilized alone and as mixture, resulting in spherical, spheroid, trigonal, polygonic, and star-like morphologies. The synthesis approach was further tested in the presence of acetate and dimethylamine as size- and shape-directing agents. With the use of transmission electron microscopy (TEM), selected area electron diffraction (SAED), x-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) absorption spectroscopy techniques, the particle size, shape, assembly, aggregation, and film formation characteristics were evaluated. NPs’ attributes were shown to be tunable by manipulating the sugar ligand selection and sugar ligand/metal-ion ratio. For instance, with an imine side group and changing the sugar moiety from cellobiose to lactose, the morphology of the Ag nanoparticles (NPs) transformed from well dispersed cubic to rough and aggregated. The introduction of acetate and dimethylamine further extended the growth pattern and morphological properties of these NPs. As examples, L5 AS, G5AS, and S5AS ligands formed spherical or sheet-like structures when used alone, which upon the use of these additives transformed into larger multicore and rough NPs, revealing their significant effect on the NP morphology. Selected samples were tested for their stability against protein corona formation and ionic strength, where a high chemical stability and resistance to protein coating were observed. The findings show a promising, benign approach for the synthesis of shape- and size-directed Au and Ag nanostructures, along with a selection of the chemistry of carbohydrate-derivatives that can open new windows for their applications.

Synthesis and Characterization of Pollen Extract Mediated Gold Nanostructures

“…However, stability of CA mediated AuNSs were not high (completely clumped within 48 h and require extensive vortexing) so further morphological analysis were not performed. This could be related to that CA extract gave lesser amount of proteins and carbohydrates than PN and JO extract, where proteins and carbohydrates can serve as stabilizing agent [36,37].…”

Luminescent Gold Nanoclusters for Bioimaging: Increasing the Ligand Complexity

“…The emergent need to find biocompatible, non-toxic, and green chemicals for the synthesis of nanobiomaterials has driven researchers to test natural molecules as ligands for MNPs [ 81 , 82 ]. Among them, proteins [ 83 , 84 ], peptides [ 85 , 86 ], amino acids [ 87 ], carbohydrates [ 88 , 89 ], and plant extracts [ 90 , 91 ] have been demonstrated to have a big impact on the biochemical, photophysical, and physical–chemical properties of MNPs. Moreover, recently, AuNCs capped with biomolecules showing superior properties have been reported in the literature.…”

Nanosensor Applications in Plant Science

“…The fungi P. italicum was successfully identified over related fungi species Trichaptum biforme , Glomerulla cingulata ( Colletotrichum gloeosporioides ), and Aspergillus nidulans . The authors concluded that this specificity resulted from the sugar ligands employed in the synthesis of the gold nanoparticles and was unaffected by their size and shapes [ 216 ].…”