Influence of pressure on the structure and luminescence properties of AMP-protected gold nanoparticles as revealed by fluorescence spectra and 2D correlation analysis

Abstract

In the present study we have applied in situ fluorescence spectroscopy, in combining with two-dimensional correlation spectroscopy (2DCOS), to investigate the dynamic fluorescence changes of adenosine 5′-monophosphate capped gold nanoclusters (AuNCs@AMP) versus pressure in solid. Several weak and overlapped spectral components, developed with pressure, are differentiated and assigned in detailed by 2DCOS analysis. In addition, the sequential spectral variations are also revealed, which take place as follows. The ligands-surface Au(I) (denoting as 450, 480 nm), surface Au(I)⋯Au(I) (as 515, 520 and 565 nm), and even the inner metal core Au–Au interactions (as 605 nm), take place at pressure range from low to high. Moreover, the pressure-induced luminescence performance is also compared between AuNCs@AMP being prepared at 60 and 80 °C, respectively. It implies that it is more stable for AuNCs prepared at 60 °C as which has better pressure tolerance. Finally, it is confirmed that the orientation of AMP at the gold surface plays a crucial role in the tuning of luminance performance, especially the emission intensity to compression.