Green synthesis of carbon dots from fish scales for selective turn off-on detection of glutathione

Carbon dots as fluorescent probes were fabricated using readily available grass carp fish scales as the carbon source via one-step synthesis based on a pyrolytic reaction. The as-prepared grass carp fish scale carbon dots (GF-CDs) exhibited good biocompatibility and excellent optical properties with a high fluorescence quantum yield of 23.8%. Glutathione (GSH) is an essential small tri-peptide molecule present in every body cell and plays a crucial role in vivo and performs a wide range of biological functions. Ag+ can effectively quench the fluorescence of GF-CDs because of the electron transfer between GF-CDs and Ag+; however, the addition of GSH can significantly increase GF-CD-Ag+ fluorescence. Because of their combination with Ag+ and GSH, GF-CDs show selective fluorescence recovery. GF-CDs can serve as fluorescent probes for GSH detection. This detection method covered a wide linear range (1.6-36.0 mu g mL-1) with the lowest detection limit of 0.77 mu g mL-1 and manifested great advantages such as a short analysis time, good stability, repeatability, and ease of operation. Carbon dots as fluorescence probes were fabricated using grass carp fish scales as the carbon source via one-step synthesis based on a pyrolytic reaction. The GF-CDs can serve as fluorescent probes for selective turn off-on detection of glutathione.