Preparation of Zein-templated gold nanoclusters and their application as a fluorescent probe for tetracycline detection

Gold nanoclusters (Au NCs) are a special type of gold nanomaterial containing multiple gold atoms. Compared to other fluorescent materials, Au NCs exhibit stronger stability and longer fluorescence lifetimes. In the synthesis of Au NCs, plant proteins offer significant advantages over animal or microbial proteins. Plant proteins are abundant, cost-effective, sustainable, and hypoallergenic. Therefore, in this study, we used Zein, a corn protein, as a template to prepare Zein-templated Au NCs using a water bath method. The optical properties of Zein-Au NCs were characterized by fluorescence spectrophotometry and UV–Vis spectrophotometry, while the morphology of the nanoclusters was examined by transmission electron microscopy. When excited at 410 nm, the maximum emission wavelength of Zein-Au NCs was observed at 490 nm. After the introduction of tetracycline, the emission peak at 490 nm was enhanced. Therefore, Zein-Au NCs can be used as a fluorescent probe for the detection of tetracycline.