▎ 摘　　要

Large amounts of hazardous and toxic substances in the environment require non-toxic, cheap, easy, rapid, and sensitive methods for their detection. Blue luminescent graphene quantum dots (GQDs) were produced by electrochemical cleavage of graphite electrodes followed by gamma irradiation in the presence of ethylenedi-amine (EDA). Modified dots were able to detect metal ions (Co2+, Pd2+, Fe3+) due to photoluminescence quenching. The highest sensitivity was detected for the sample irradiated at a dose of 25 kGy. The limits of detection (LODs) were 1.79, 2.55, and 0.66 mu mol L-1 for Co2+, Fe3+, and Pd2+, respectively. It was observed that GQDs irradiated at 200 kGy act as an ultra-sensitive turn-on probe for Malathion detection with LOD of 94 nmol L-1. Atomic force microscopy images proved the aggregation of GQDs in the presence of the investigated metal ions. Results obtained by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and LIVE/ DEAD cytotoxicity test indicated that GQDs irradiated with EDA are not toxic towards MRC-5 cells, which makes them a promising, eco-friendly and safe material for sensing application.