Journal Article

Comparison of Toxicity and Cellular Uptake of CdSe/ZnS and Carbon Quantum Dots for Molecular Tracking Using Saccharomyces cerevisiae as a Fungal Model

Otsus, Maarja, Kozlova, Jekaterina, Färkkilä, Sanni M. A., Mäeorg, Uno, Mortimer, Monika, Kurvet, Imbi, Jaaniso, Raivo, Kahru, Anne, Kasemets, Kaja, Kiisk, Valter, Kikas, Arvo

2023

Overview

Plant resource sharing mediated by mycorrhizal fungi has been a subject of recent debate, largely owing to the limitations of previously used isotopic tracking methods. Although CdSe/ZnS quantum dots (QDs) have been successfully used for in situ tracking of essential nutrients in plant-fungal systems, the Cd-containing QDs, due to the intrinsic toxic nature of Cd, are not a viable system for larger-scale in situ studies. We synthesized amino acid-based carbon quantum dots (CQDs; average hydrodynamic size 6 ± 3 nm, zeta potential −19 ± 12 mV) and compared their toxicity and uptake with commercial CdSe/ZnS QDs that we conjugated with the amino acid cysteine (Cys) (average hydrodynamic size 308 ± 150 nm, zeta potential −65 ± 4 mV) using yeast Saccharomyces cerevisiae as a proxy for mycorrhizal fungi. We showed that the CQDs readily entered yeast cells and were non-toxic up to 100 mg/L. While the Cys-conjugated CdSe/ZnS QDs were also not toxic to yeast cells up to 100 mg/L, they were not taken up into the cells but remained on the cell surfaces. These findings suggest that CQDs may be a suitable tool for molecular tracking in fungi (incl. mychorrhizal fungi) due to their ability to enter fungal cells.

• Publisher: MDPI AG,MDPI
• Subject: Amino acids / Cadmium selenides / Carbon / Carbon dots / Essential nutrients / Fourier transforms / Fungi / molecular tracking / mycorrhizal fungi / Nitrogen / Nutrients / Plant resources / Quantum dots / Saccharomyces cerevisiae / Spectrum analysis / Toxicity / Tracking / X-rays / Yeast / Zeta potential / Zinc sulfide