Eco-friendly nitrogen-doped carbon dots from Sauropus androgynus leaf extract: a sustainable tool for mung bean germination, bioimaging and tissue culture enhancement

This work reports the impact of carbon dots (CDs) on plant growth and their application in tissue culture media. Nitrogen-doped CDs (NCDs) were synthesized from the extract of Sauropus androgynus leaves using the hydrothermal method. The synthesized NCDs were characterized using UV-visible absorption spectroscopy, Photoluminescence spectroscopy, High-resolution transmission electron microscopy, Raman spectroscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Cytotoxicity was assessed using an MTT assay in CHO-K1 cells, confirming the low cytotoxicity of NCDs. Vigna radiata L. (mung bean) seed priming was performed with varying concentrations of NCDs, and the results showed a significant enhancement in germination rate and seedling vigor compared with untreated controls. The fluorescence imaging technique was utilized to confirm the absorption and translocation of NCDs within plants by exploiting their fluorescence. The applicability of NCDs was extended to plant tissue culture, demonstrating improvements in in vitro seed germination, shoot multiplication, callus induction, and callus culture proliferation. Our findings validated the potential of NCDs as efficient bioimaging tools, non-toxic growth promoters for plant growth and tissue culture applications. They paved the way for their integration into sustainable agriculture and biotechnology practices.