ECOTOXICOLOGICAL BIOASSAYS IN QUANTUM DOTS NANOPARTICLES WITH THE MICROALGAE Pseudokirchneriella subcapitata: ECOTOXICOLOGICAL BIOASSAYS IN QUANTUM DOTS NANOPARTICLES WITH THE MICROALGAE Pseudokirchneriella subcapitata

Quantum dots (QDs) nanoparticles are increasingly being used for electronics devices,solar energy generation and medical imaging applications. While the new propertiesof nanoparticles are more and more studied, little is known about their interactionswith aquatic organisms. As a primary producer, phytoplankton serves as an importantcomponent of the aquatic ecosystem. According to our bibliographic search, no reportswere found on the evaluation of ecotoxicity of QDs inPseudokirchneriella subcapitata.In this study, QDs were evaluated using ecotoxicological bioassays (cellular toxicitymodels and potential indicators of the impact in aquatic ecosystems) with the microalgaeP. subcapitata. With ecotoxicity concentrations of 0, 1, 2, 3 and 4 nM of QDs with P.subcapitata at 96 h exposure a mean inhibitory concentration of growth (IC50) of themicroalgae P. subcapitata IC50 = 1,94 nM of QDs(a) was obtained for orange fluores-cence; IC50 = 1.68 nM of QDs(r) for red fluorescence, and IC50 = 2.03 nM of QDs(v)for green fluorescence, observing the following order of sensitivity: QDs (r) ˃ QDs (a)˃ QDs (v). The toxicity of the QDs are evident by the type of fluorescence detectedin the standard solution 4 M of QDs and 10 -1M. The images of confocal microscopyof fluorescence showed adhesions of QDs in microalgal cells until low concentrationswith high growth rates of P. subcapitata at concentrations of 1 nM compared to con-centrations of 10-1 M of QDs nanoparticles with low growth rates.