Lysosome-targetable brightly green fluorescence carbon dots for real-time monitoring in cell and highly efficient removal in environment of hypochlorite

Abstract

Due to the lacks of lysosome localization group and reaction/interaction site for hypochlorite (ClO-) on the surface of the carbon dots (C-dots), no C-dots-based lysosome-targeted fluorescence probes have, so far, been reported for real-time monitoring intracellular ClO-. In this work, 1,3,6-trinitropyrene (TNP) was used as a precursor to prepare C-dots with maximum excitation and emission wavelengths at 485 and 532 nm, respectively, and quantum yield ∼ 27% by a hydrothermal approach at 196 °C for 6 h under a reductive atmosphere. The brightly green C-dots can sensitively and quickly respond to ClO- in aqueous solution through surface chemical reaction, showing a linear relationship in the range of 0.5–120 μΜ ClO- with 0.27 μΜ of limit of detection (LOD). Most significantly, the C-dots can localize at intracellular lysosome to image ClO- in lysosomes. Also, the magnetic nanocomposites (C-dots@Fe3O4 MNCs) were fabricated via a simple electrostatic self-assembly between Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) and C-dots for highly efficient removal of ClO- in real samples. Therefore, lysosome-targetable C-dots-based probes for real-time monitoring ClO- were successfully constructed, opening up a promising door to investigate the biological functions and pathological roles of ClO- at organelle levels.