Synthesis of water-soluble fluorescent carbon dots from Setcreasea purpurea boom and its application for Br 2 detection

Fluorescent carbon dots (CDs) were successfully synthesized via pyrolysis of Setcreasea purpurea boom , providing a simple and convenient method for the preparation of CDs without using toxic or expensive materials. The as-synthesized CDs exhibit excellent water-soluble property, good photostability, and higher fluorescence quantum yield (18%), which makes the as-obtained CDs serve as fluorescent inks for printing luminescent patterns for anti-counterfeiting. In addition, the fabricated CDs have sensitive and selective response to molecular bromine (Br 2 ) and have been successfully used for the detection of Br 2 in brine, which is based on the Br 2 -induced fluorescence quenching of CDs. According to UV-visible and transient state fluorescence spectroscopy, the fluorescence quenching of as-prepared CDs was due to the dynamic collision between the CDs and Br 2 .