Sustainable large-scale synthesis of biologically active sulfur quantum dots using sublimed sulfur

The large-scale synthesis of ethylenediamine-capped sulfur quantum dots was performed using a sustainable method that utilizes sublimated sulfur waste as a sulfur precursor and recycles ∼70% of the solvent and >50% of the water used in the process. This process achieved a high conversion efficiency of 21% and a high photoluminescence quantum yield of 79.8%, one of the highest reported, involving a reaction volume at least five times larger than previously reported methods. The SQDs exhibited biological activity with low cytotoxicity, high antioxidant and antibacterial properties, and significant anticancer activity.