Pressure-Induced Fluorescence Enhancement of the BSA-Protected Gold Nanoclusters and the Corresponding Conformational Changes of Protein

We investigated the pressure-induced fluorescence enhancement of BSA-protected gold nanoclusters, AuNCs@BSA, and the corresponding conformational changes of ligand protein by in situ fluorescence and IR spectral measurements. It is documented that the fluorescence enhancement of AuNCs@BSA is essentially attributed to the conformational changes of the ligand, which undergoes substantial secondary and tertiary structural changes. Under compression BSA loses more buried α-helical structure, while it changes oppositely in the AuNCs@BSA as the protein adopts a more flexible conformational state at the boundary surface of gold nanoclusters. The present work will be helpful to understand the fundamental mechanism and to reveal the important factors of ligands in nanoclusters, which are hope to improve the luminescence efficiency of gold nanoclusters in final.