"Vigna radiata" based green C-dots: Photo-triggered theranostics, fluorescent sensor for extracellular and intracellular iron (III) and multicolor live cell imaging probe.

" Vigna radiata " based green c-dots for photo dynamic therapy (PDT), multicolor imaging and sensing of Fe3+. • Nitrogen doped C-dots were prepared using " Vigna radiata " as a sole carbon precursor. • The as synthesized N@VRCD exhibits excellent quantum yield of ∼58%. • N@VRCD selectively sense Fe3+ with LOD of 140 nM. • N@VRCD acts as photosensitizer upon irradiation by generating photo-induced singlet oxygen. Fluorescent C-dots have drawn increasing attention due to their superior properties such as high aqueous solubility, optical absorptivity, favorable biocompatibility and appreciable photoluminescence. Nature offers various precursors for the synthesis of green C-dots like fruits, vegetables, flowers, animal derivatives and many more. Herein, nitrogen doped C-dots (N@VRCD) were developed by economical, one step hydrothermal method using " Vigna radiata " sprouts as sole carbon precursor and ethylenediamine as the nitrogen source, which was optimized for enhanced optical properties. To the best of our knowledge, N@VRCD shows excellent quantum yield ∼58%. Importantly, N@VRCD also exhibits significant light induced phototoxicity to cancerous cells which enable the possibility of using it as a potential theranostics agent. Further, the N@VRCD displays highly sensitive and selective sensing behaviour towards Fe3+ ions by getting fluorescence "turn-off" with the limit of detection as low as 140 nM. Moreover, N@VRCD shows biocompatible and hemocompatible nature with a potential of multicolor live cell imaging and intracellular Fe3+ detection which was validated by confocal microscopy and flow cytometry. [ABSTRACT FROM AUTHOR]