In recent years, carbon-based nanomaterials, especially carbon dots, have attracted significant interest in nanoagriculture for various applications owing to their outstanding properties. Therefore, in this study, we employed green chemistry to synthesize colloidally stable blue-fluorescent 5–8 nm carbon dots using sweet basil leaves via a hydrothermal method. We also studied their physicochemical properties, such as absorption, fluorescence, functional groups, stability, size, and surface charges. Three different dilutions were prepared and incubated with fenugreek seeds to evaluate their impact by assessing the length and weight of the roots and stems. The 1:5 dilution factor had a more promising impact on seedling growth. Therefore, this study shows that carbon dots can be effectively used as a nano-priming agent based on their biocompatibility, biodegradability, and biostimulant properties. • Blue fluorescent carbon dots using sweet basil ( Ocimum basilicum) leaves. • Highly colloidal and stable carbon dots of 5–8 nm in size. • Promote fenugreek ( Trigonella foenum-graecum ) seedlings growth. • Carbon dots as an effective nano-priming agent.
Monreal-Contreras et al. (2026) studied this question.