Dual microenvironmental parameter-responsive lysosome-targeting carbon dots for the high contrast discrimination of a broad spectrum of cancer cells

The development of new carbon dots (CDs) for fluorescence-based cancer diagnosis has recently attracted extensive attention. Diagnosis methods based on ligand-receptor fluorescence suffer from the heterogeneity of receptor expression. Changes in the microenvironments of cancer cells provide opportunities for accurate and broad-spectrum cancer diagnosis. The lysosomes in cancer cells have lower polarity and higher viscosity than normal cells. Based on these two key microenvironmental parameters, dual-responsive CDs with inherent lysosome-targeting ability were synthesized via one-step hydrothermal treatment. The CDs exhibit many advantageous properties including facile synthesis, good water solubility, pH-independent emission, excellent photostability, good biocompatibility, and wash-free imaging ability. The CDs were successfully employed in the fluorescence-based discrimination of a broad spectrum of cancer cells from normal cells with high contrast. The CDs are promising candidates for use in the field of cancer diagnosis. By taking advantage of lower polarity and higher viscosity of cancerous lysosomes, polarity and viscosity dual microenvironmental parameter-responsive lysosome-targeting CDs were rationally prepared and showed great potential in high contrast discrimination of a broad spectrum of cancer cells from normal cells.