Multifunctional nitrogen-doped carbon dots for HS- sensing and mitochondrial-targeted imaging

Hydrogen sulfide ions (HS-) are an important endogenous ion species found in the human body, with HS- concentration changes known to play an important role in regulating various physiological activities. This study describes a simple strategy for preparing N-doped carbon dots (NCDs) using hydrothermal synthesis that utilize 3-aminophenol and tartaric acid. Aqueous solutions of these NCDs produced a green fluorescence under excitation at 494 nm and demonstrated good photostability under different NaCl concentrations, pH values and UV irradiation time. Moreover, the NCDs as probe also showed high sensitivity and selectivity for detecting HS-. Additionally, these NCDs exhibit excellent biocompatibility and low cytotoxicity making them ideal for cellbased imaging and colocalization experiments that was further verified the ability of these NCDs to cross the cell membrane and label the mitochondria. More importantly, we can successfully realize the detection and visualization of exogenous HS- in mitochondria. Thus, these NCDs-based probe can reasonably be expected to replace common commercial probe especially in the organelle imaging and fluorescent visualization of the mitochondria.

Automated summary

This study presents a simple strategy for preparing N-doped carbon dots (NCDs) using hydrothermal synthesis. These NCDs, as probes, exhibit high sensitivity and selectivity for detecting and visualizing HS-. Additionally, NCDs demonstrate good photostability, biocompatibility, and low cytotoxicity.