Target-oriented synthesis of high synthetic yield carbon dots with tailored surface functional groups for bioimaging of zebrafish, flocculation of heavy metal ions and ethanol detection

Target-oriented synthesis of multifunctional carbon dots with high synthetic yield is still a challenge. Herein, the acrylamide (AM) and acrylic acid (AA) which containing unsaturated carbon–carbon double bonds (C[dbnd]C) and different functional groups were chosen as switches for the directional synthesis of carrot derived carbon dots with water-solubility (WCDs) and ethanol-solubility (ECDs). The synthetic yield of WCDs and ECDs could reach up to 31.19% and 51.94% by the directional hydrothermal carbonization reaction adjusted by the free radical polymerization. Specifically, the WCDs inherited negative charge, amino group and high N element from the AM, while AA endowed the ECDs with electronic neutrality, ester group and low N content. Furthermore, the WCDs as probes for assessment of uptake and metabolism of zebrafish, integrated of flocculation and detection of the WCDs on heavy metal ions, and the ethanol detection performance of the ECDs in medical alcohol disinfectant were detailly investigated. Therefore, the high synthetic yield CDs prepared by target-oriented synthesis have application potential in bioimaging, flocculation and detection of heavy metal ions, and ethanol detection.