One-pot synthesis of nuclear targeting carbon dots with high photoluminescence

Carbon dots (CDs) are novel fluorescent nanomaterials with good water solubility, high resistance to photobleaching and low toxicity. While, there are few studies elaborate on the relationship among reaction conditions, properties and applications of CDs. In this study, a series of CDs are synthesized through a one-pot hydrothermal method, and different reaction conditions are carried out to study the influencing factors of CDs properties. As a result, with the increase of temperature and reaction time, the particle size and zeta potential of CDs increased, the maximum emission wavelength red-shifted and the fluorescence quantum yield (QY) improved. Among them, CD₃₀₀₆ has good water solubility and highest QY of 81.4%, which is beneficial for its applications in bioimaging and ion detection. CD₃₀₀₆ is almost nontoxic in cells at a concentration of 500 µg/mL. In addition, the positive charged CD₃₀₀₆ shows nuclear targeting potential because of its combination with DNA through electrostatic interaction in nucleus. The properties of CDs can be greatly enhanced by controlling reaction conditions, and it provides great application prospects.