A versatile synthetic strategy for Mg-doped carbon dots derived from the traditional Chinese herb mulberry and its application in osteoblastic differentiation

•Mg-CDs were synthesized by different hydrothermal routes using the traditional Chinese herb mulberry as the carbon source and MgCl2 as the magnesium dopant.•A series of experiment about macroscopic fluorescence property and microstructure were performed on the synthesized samples in order to obtain an optimized method for the synthesis of Mg-CDs.•This study provides a good example of the preparation of metal ion-doped traditional Chinese herbal CDs. In this work, Mg-doped CDs were synthesized by different hydrothermal routes using the traditional Chinese herb mulberry as the carbon source and MgCl2·6H2O as the magnesium dopant. A series of morphological (TEM, SEM), microstructural (XRD), and spectroscopic characterizations (FTIR, XPS, EDS, UV–Vis, PL, Zeta, and so on) of the prepared CDs were carried out, and very self-consistent results were obtained. The Mg-doped CDs (CDs2) samples with small size, uniform dispersion, high stability, excellent fluorescence performance, and simple preparation were screened, and applied to the osteogenic differentiation study of MC3T3 cells in vitro. The results showed that Mg-doped CDs could well induce osteoblast differentiation and bone matrix mineralization in vitro, the preliminary osteogenic mechanisms can be assumed that Mg-doped CDs activate the PERK signaling pathway to upregulate the expression of osteoblast gene markers. The Chinese herb Mg-doped CDs show great potential for future application in bone repair by combining them with scaffold materials..