Green Preparation of Fluorescent Carbon Dots from Water Chestnut and Its Application for Multicolor Imaging in Living Cells

A green approach was developed from the preparation of fluorescent carbon dots (CDs) by using water chestnut as precursor. The preparation of CDs was performed by simple pyrolsis. The as-prepared CDs are uniform in size, and the quantum yield was 12.6% by using quinine sulfate as the reference. Significantly, not only the precursor of CDs and whole synthesis procedure was green, but also the CDs obtained here exhibited various advantages including high fluorescent quantum yield, excellent photo stability, non-toxicity and satisfactory stability. Additionally, the CDs were employed as cell-imaging agents. The inherent cytotoxicity of CDs was evaluated using HepG2 cell, and the cell viabilities were estimated to be greater than 90% upon addition of the CDs over a wide concentration range of 0-200μg mL -1 . It was then successfully applied for the fluorescence imaging of HepG2 cells. Thus, the as-prepared CDs hold great promise to broaden applications in fluorescence probe and bioimaging.