Multicolor-emitting carbon dots from Malus floribunda and their interaction with Caenorhabditis elegans

The Malus floribunda fruit extract and aqueous ammonia have been employed as carbon and nitrogen resource material, respectively to synthesize nitrogen-doped carbon dots (N-CDs) by a facile one-step hydrothermal method. The N-CDs exhibit excellent lattice fringes with a d-spacing of 0.21 nm. The NCDs have tunable fluorescence emission with redshift from 390 to 501 nm as the excitation wavelength increased from 300 to 460 nm. Finally, N-CDs have been used as a fluorescent probe to image Caenorhabditis elegans (nematode) in vivo model. It showed low cytotoxicity and remarkable performance due to its good fluorescence quantum yield (19%). Moreover, the obtained N-CDs are potential candidates for biomedicine-related studies. (C) 2019 Elsevier B.V. All rights reserved.