Boosting the Photoluminescent Properties of Protein-Stabilized Gold Nanoclusters through Protein Engineering

This work reports on the use of protein engineering as a versatile tool to rationally design metal-binding proteins for the synthesis of highly photoluminescent protein-stabilized gold nanoclusters (Prot-AuNCs). The use of a single repeat protein scaffold allowed the incorporation of a set of designed metal-binding sites to understand the effect of the metalcoordinating residues and the protein environment on the photoluminescent (PL) properties of gold nanoclusters (AuNCs). The resulting Prot-AuNCs, synthesized by two sustainable procedures, showed size-tunable color emission and outstanding PL properties. In a second stage, tryptophan (Trp) residues were introduced at specific positions to provide an electronrich protein environment and favor energy transfer from Trps to AuNCs. This modification resulted in improved PL properties relevant for future applications in sensing, biological labeling, catalysis, and optics.

Automated summary

Protein engineering was used to design metal-binding proteins for the synthesis of highly photoluminescent protein-stabilized gold nanoclusters, with the designed metal-binding sites influencing the photoluminescent properties of the AuNCs. The resulting AuNCs showed size-tunable color emission and outstanding photoluminescent properties, with the introduction of tryptophan residues leading to improved properties for potential applications in sensing, biological labeling, catalysis, and optics.