Synthesis, optical properties, cytotoxicity and Aspergillus oryzae application of bio-synthesized ZnS quantum dots

ZnS quantum dots (QDs) were synthesized using Aspergillus oryzae (A. oryzae) as raw material for the first time. The crystal structure, photoluminescence (PL) properties, cytotoxicity, and A. oryzae application of ZnS QDs were studied in detail. The results displayed that ZnS QDs had a wurtzite crystal structure with blue emission, and the average crystalline size was about 3.96 nm. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and A. oryzae application showed that ZnS QDs had low cytotoxicity and good biocompatibility, and it acted as an activator to promote the biomass, kojic acid, glutathione, PL intensity, and extracellular proteins of A. oryzae. This study can supply a new idea for the synthesis of QDs and increase the output of A. oryzae or other microorganisms.