Determination of possible nanotoxicological effects of bismuth sulfide (Bi2S3) and cobalt (Co) nanoparticles on model organisms

Nanomaterials, invisible particles with unique physical, chemical, and biological properties, have numerous applications in various fields. However, their toxic effects on aquatic ecosystems remain unclear. A study synthesized Bismuth sulfide (Bi2S3) nanoflowers and Cobalt (Co) nanosheets using microwave-based hydrothermal processes investigated their genotoxic effects on Cyprinus carpio and Daphnia magna using XRD, SEM, and FTIR analysis.Made according to the guidelines of the nanomaterials used (Organization for Economic Cooperation and Development). In the first part, LC50value of Bi2S3 nanoflowers at the end of 96th hour was determined as 350 mg L -1 by probit analysis and three subletal concentrations (35, 87 and 175 mg L -1) were selected according to LC50value. According to LC50value, Bi2S3 nanoflowers are not found toxic to aquatic organisms according to EU Directive 93/67/EEC classification scheme. In the genotoxicological evaluation of the sublethal concentrations of Bi2S3 nanoflowers, DNA damage and micronucleus disorders of 35 and 87 mg L -1 dose groups; while it was found similar to the control group; Higher DNA damage and erythrocyte abnormalities were detected in the 175 mg L -1 Bi2S3 group compared to the control and other dose groups. In the second part, possible cytotoxic and genotoxic effects of synthesized cobalt nanoleaves on our other model organism, Daphnia magna, were investigated. The model organism was exposed to different concentrations of Cobalt (Co) nanoleaves(1, 5, 10, 15, 20 and 25 µg L-1 ) for 24, 48, 72 and 96 hours and at the end of the 96th hour, the LC50value was determined by probit analysis. It was determined as 9,705 µg L-1. According to the toxicity levels determined by the GHS, Cobalt(Co) nanoleaves are in the highly toxic category.Safe Administration Rate (SAR) and Safety Factor (SAFE) coefficients were calculated with the 96-hour acute toxicity test and found to be 0.025 and 0.243, respectively. In the subacute trial, DNA damage (53.00±0.94%) at the highest concentration (2.5 µg L -1) of Co nanoleaves was approximately 2 times higher than that of the control group (28.33±1.52%). ISO10993-5, Cobalt nanoleaves are classified as cytotoxic for certain concentrations on D. magna. This thesis is the first study to reveal the effects of Bi2S3 nanoflowers and Co nanoleaves on aquatic life and to reveal concrete data on their toxicology, and more systematic studies are needed on the environmental effects and risks of these nanomaterials.