Green synthesis of multifunctional carbon dots for anti-cancer and anti-fungal applications

Carbon dots (CDs) have become popular nanomaterials in biomedical and agricultural fields. Herein we synthesized multifunctional CDs which showed anti-cancer and anti-fungal activities. The low cytotoxicity, stable fluorescence and high photothermal conversion efficiency enable the CDs with imaging-guided photothermal therapy. The CDs also exhibited intrinsic anti-fungal activity even at a low concentration, i.e., 40 mg·L−1 of CDs induced 20% mortality in cucumber downy mildew. Moreover, the large π-conjugated nanostructure and the richness of amino and hydroxyl groups make them a powerful delivery platform for flumorph (a fungicide) with a high loading efficiency of 47.18%. Meanwhile, the heat converted from the light can accelerate the release of flumorph from CDs, and thus efficiently kill fungus.