An Evaluation Research About Effects of Characterized Cadmium Selenide (CdSe) and Lead Selenide (PbSe) Quantum Dots on Brine Shrimp (Artemia salina).

Quantum dots (QDs), such as cadmium selenide (CdSe) and lead selenide (PbSe) exhibit excellent optical, magnetic and chemical properties due to their extremely size (ca. 1-10 nm) and are attractive semiconductor nanomaterials for optical studies and energy storage. In this study, aqueous synthesis of CdSe and PbSe QDs in a size range of 2-10 nm was described. Synthesized QDs were characterized using SEM and TEM, DLS, zeta potential, FTIR, EDX and XRD. Highest accumulation (72.5 ± 5.8 mg L-1) of PbSe QDs occurred at 10 ppm suspensions. In general accumulation increased up to 48 h exposure then fluctuate tended to decline. For CdSe QDs, accumulation tended to decrease for 72 h exposure except that for 5 ppm groups. For the elimination period, in general, the elimination levels of PbSe and CdSe QDs from exposed individuals decreased (p < 0.05) even it has some fluctuate.

Assessment of Oxidative Stress on Artemia salina and Daphnia magna After Exposure to Zn and ZnO Nanoparticles.

In this study, the effect of zinc nanoparticles (Zn NPs) and zinc oxide nanoparticles (ZnO NPs) on Artemia salina and Daphnia magna, the primary consumer organisms were investigated. In this sense, investigation of trophic transfer and ecological sustainability potentials among living things, such as fish and crustaceans that are at the top of the food chain were also aimed. Zn NPs in the size of 40-60 nm and 80-100 nm and ZnO NPs (10-30 nm) were administered to A. salina and D. manga (respectively in total 105000 and 14000 individuals) in seven groups (Control, 0.2, 1, 5, 10, 25 ve 50 ppm) with three repetitions for a period of 72 h. Intensive and possible misuse of nanoscale materials is one of the biggest threats to the environment and all living things worldwide. Therefore, the control mechanisms for the use of NPs need to be established.

Effects of Zn and ZnO Nanoparticles on Artemia salina and Daphnia magna Organisms: Toxicity, Accumulation and Elimination.

In the study, Zn in the size of 40-60 nm and 80-100 nm and ZnO in the size of 10-30 nm were applied to A. salina and D. magna individuals in 7 groups with 3 repetitions. Measurements were made at 24th, 48th and 72nd hours and elimination values were examined at +24 h. LC50 values of NPs were determined and chemical analysis (metal accumulation and elimination), ion quantities which were given to the environment and the survival rates of organisms were determined after the exposure. According to the results of phase contrast microscopy, it was found that both experimental organisms absorbed the NPs in the medium level. In the toxicity results of D. magna, it can be said that Zn NP (40-60 nm) has a highly toxic effect only at 50 ppm concentration for 48 h and lethal dose can be accepted as of 5 ppm at the end of 72 h. In A. salina individuals, it is clearly seen that there is an increase in mortality in organisms parallel to the dose increase. Although all NPs were applied to organisms in low doses corresponding to environmental values, it was observed that toxic effect was in parallel with the increase in time. It is clearly known that there is the inverse proportion between the size of NPs and the toxic effect. The smaller the size of NPs is, the higher the toxic effect becomes When the results of Zn accumulation and elimination of A. salina and D. magna individuals exposed to the Zn and ZnO NPs were examined; it was found that accumulation and elimination occurred in parallel with the increase in concentration at each application hour and elimination. Intensive and possible misuse of nanoscale materials is one of the biggest threats to the environment and all living things worldwide.