Facile one-pot synthesis of near-infrared luminescent gold nanoparticles for sensing copper (II).

Novel near-infrared luminescent gold nanoparticles (NIRL-AuNPs) were synthesized by a simple, rapid and one-pot procedure. The driving force for the formation of these NIRL-AuNPs was attributed to the heat-assisted reduction of a gold(I)-thiol complex. These gold nanoparticles were characterized by TEM, DLS, FT-IR and XPS. Luminescence studies indicated that these NIRL-AuNPs exhibited strong emission with peak maximum at 810 nm, microsecond-range photoluminescence lifetime, large Stokes shifts (>400 nm) and stabilities towards photobleaching and chemical oxidation. The sensing application for Cu(2+) ions of these NIRL-AuNPs was demonstrated. These as-synthesized gold nanoparticles will provide a new NIRL nanomaterial for in vitro and in vivo applications.