Bioimaging application and growth-promoting behavior of Auxin-derived carbon dots on cancer cell and seed performance

Auxin-derived carbon dots (Aux-CDs) were synthesized and evaluated for their dual functionality in biomedical and agricultural contexts. One-step hydrothermal synthesis was employed for the first time to produce eco-friendly and cost-effective Aux-CDs. The approach involves introducing a mixture of Auxin and water into the reactor. The fluorescence in the Aux-CDs was initially confirmed using a UV transilluminator. Physicochemical characterizations were evaluated via UV-Vis spectrophotometry (absorbance at 470 nm), zeta potential measurement (-37.8 mV), photoluminescence, scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR). The total quantum yield exhibited was 43%, and the transmission electron microscopy (TEM) showed a size range of approximately 10 nm. In cancer cells, the MTT assay revealed that Aux-CDs demonstrated low cytotoxicity in 4T1 cells up to 10 µg/mL. The fluorescence accumulation indicates the internalization of the Aux-CDs by 4T1 cells. In seed performance, we examined the effects of Aux-CDs on through nanopriming. The wheat seeds (the Drum and Ehsan varieties) were incubated with CDs to check the absorption of Aux-CDs by them. The fluorescence was observed under a UV-transilluminator in the growing parts of seeds, indicating the absorption of Aux-CDs during wheat growth. Cancer cell and wheat imaging showed that fluorescent Aux-CDs could be used as a bioimaging agent. Additionally, Aux-CDs significantly improved seed germination percentage and the performance index in the Drum and Ehsan varieties in low concentration (1 µg/mL) compared to high concentration (10 µg/mL). Consequently, Aux-CDs synthesized via a one-step hydrothermal method exhibit high quantum yield and biocompatibility, and can act as multifunctional nanomaterials for bioimaging and plant growth enhancement in biomedical and agricultural research.