Photocatalytic synthesis of intensely photoluminescent gold nanoclusters and application in cell imaging

In this article, a facile and rapid method was developed to synthesize intensely photoluminescent gold nanoclusters (AuNCs) based on photocatalytic reduction. Using (5-mercapto-1,3,4-thiadiazol-2-ylthio)acetic acid (TMT) that is a photosensitive material as the ligands, AuNC@TMT, with high photoluminescence quantum yield (19.7%), were prepared. The average diameter of gold core is 1.69 ± 0.22 nm. The maximum excitation and emission wavelengths of AuNC@TMT are at 422 and 516 nm, respectively. The mechanism of photocatalytic reduction is preliminarily understood. Under UV lamp with 365 nm irradiation, Au(Ι)-TMT complex occurred with electron transfer from TMT to Au(Ι), which was reduced to Au(0) as the gold core of AuNC. Thus, it indicates that the photosensitive and electron transport materials with a thiol group will be superior ligands for synthesis of intensely photoluminescent AuNCs.