Synthesis and Optical Characterization of Thermosensitive, Luminescent Gold Nanodots

A facile one-pot synthesis for preparing thermosensitive, luminescent gold nanodots with diameters of 1–2 nm is presented. The influence of the alkyl chain length of the surface ligands (alkyl thiols) on the optical properties of the gold nanodots was investigated. The synthesized gold nanodots show strong thermosensitive photoluminescence. A photoluminescence quantum yield of 16.6% was observed at room temperature, which could be improved to a value of 28.6% when cooling the gold nanodot solutions to −7 °C. The synthesized thermosensitive, luminescent gold nanodots are interesting candidates for optoelectronic devices, medical imaging, sensing, or security labels.