Nitrogen-Doped Carbon Dots via Hydrothermal Synthesis: Naked Eye Fluorescent Sensor for Dopamine and Used for Multicolor Cell Imaging

The development of a novel uncomplicated sensor for sensitive and selective detection in biomedical analysis is necessary. This study demonstrates the preparation of nitrogen-doped carbon dots (N—C dots) via hydrothermal synthesis as a naked eye fluorescent probe for selective and sensitive detection of dopamine (DA). The successful synthesis of N—C dots was confirmed using various microscopic and spectroscopic techniques. In addition, N—C-dot-incorporated gel strips were prepared through a simple approach for naked eye detection of dopamine. The linear range for detection of dopamine was 2–20 μg/mL with a detection limit as low as 1.97 μg/mL. Moreover, N—C dots showed a low toxicity toward HeLa cells, demonstrating their relevance in multicolor cell imaging. The developed probe was also utilized for quantitative determination of dopamine in a commercial pharmaceutical sample with adequate results.