Quantum dots (QDs) are tiny semiconductor particles that are only a few nanometers in size. They are made of materials such as cadmium selenide (CdSe) and zinc sulfide (ZnS) [1]. QDs have unique electronic and optical properties that make them useful in a wide range of applications, but their small size also makes them more toxic than larger particles. This is because smaller particles have a higher surface-to-volume ratio, making them more reactive and more likely to interact with living cells. Additionally, smaller particles can more easily cross cell membranes and enter cells, where they can cause damage [2]. There is growing concern about their potential toxic effects on living organisms. The study of the toxic effects of quantum dots on brown trout (Salmo trutta fario) is an important contribution to the field.
Catalase (CAT) is an enzyme that catalyzes the breakdown of hydrogen peroxide (H2O2) into water and oxygen. This enzyme is vital in safeguarding cells from harm caused by an imbalance between the generation of reactive oxygen species (ROS) and the cells' ability to neutralize them [3]. When an organism is exposed to oxidative stress, the activity of CAT increases to neutralize the hydrogen peroxide that is produced as a result of the stress. Therefore, measuring the activity of CAT can provide an indication of the level of oxidative stress in a particular organism or tissue.
The aim of this study is to identify CAT activity in the liver of Salmo trutta fario after exposure to QDs. The CAT activity was measured using a colorimetric method. The results showed that exposure to QDs resulted in variation of CAT activity during exposure periods compared to the control group. Understanding the potential toxic effects of QDs on aquatic organisms is crucial for the protection of the environment, human health, and the sustainability of industries that rely on QDs.