Using Cu2+ ions as a detection material to verify the synthesis mechanism of Au nanoclusters mediated by wool keratin and silk fibroin resilience network

Abstract

Nanoclusters, with their ultrasmall sizes, have emerged as an indispensable tool in designing structural materials with a wide range of applications, but predicting the synthesis mechanism and structures remains challenging. This work delineates a synthesis mechanism of gold nanoclusters (AuNCs), which is realized by functionalizing a wool keratin (WK) and silk fibroin (SF) resilience network structure via self-assembly with controllable microstructure transformation. We synthesized such AuNCs by reducing the thiol groups of WK into WK@AuNCs and then entering the WF&SF resilience framework during the reconstruction, achieving WK@AuNCs/WK&SF with high fluorescence intensity for selective quenching of heavy metal Cu2+ ions. Further investigation indicated that α-helix and β-crystallites resulted in a soft–hard molecular segment denoted as WK&SF resilience network, which held and separated the WK@AuNCs into the nanocages. Owing to the synergism of these features, WK@AuNCs/WK&SF displayed superior fluorescence performances compared with WK@AuNCs.