A new gold peptide-based nanomaterial has been developed which shows promise to reduce small-molecule pollutant p-nitrophenol to p-aminophenol in less than two minutes. Gold-peptide composites have also shown the ability to act as catalysts in biocatalysis. The potential uses of these materials include sensing, imaging, and catalysis.
Synthetic peptides are easy to synthesize and have a favorable pharmacokinetic profile. In addition, they are used to access biological materials. Peptides can bind biomolecules and amines as well as function as reducing agents and stabilizers.
In order to prepare gold-peptide superstructures, tyrosine-rich short peptides are used. These peptides have high assembling and mineralizing properties. They also exhibit conformationally constrained amino acids that are effective tools to stabilize AuNPs.
A variety of peptide-gold nanocomposites have been reported in the literature. However, the mechanism of their reduction process remains unclear. Hence, the mechanism requires further investigation.
One possible mechanism is the interaction between the gold nanoparticles and the lysine amino acids. As a result, the peptides can hold the nanoparticles in the nanofibers. Another mechanism is electrostatic interactions between the components. For example, the peptides can act as an electrostatic capping and stabilizing agent, and the gold nanoparticles can be reduced.
Gold nanoparticles are typically face-centered cubic in nature. They have a consistent d-spacing. Their average size is 5.16 nm. UV-Vis spectroscopy and EDS characterizations confirm the presence of gold elements on the nanoparticle surface. FTIR spectroscopy and XPS have also been used to study their specific interactions with the peptide.