Fluorescent Oxygen-Doped g-C₃N₄ Quantum Dots for Selective Detection Fe³⁺ Ions in Cell Imaging

Herein, oxygen-doped g-C₃N₄ quantum dots (OCNQDs) were fabricated through sintering and ultrasonic-assisted liquid-phase exfoliation methods. The obtained OCNQDs with uniform size show high crystalline quality, and the average diameter is 6.7 ± 0.5 nm. Furthermore, the OCNQDs display excellent fluorescence properties, good water solubility, and excellent photo stability. The OCNQDs as fluorescence probe show high sensitivity and selectivity to Fe³⁺ ions. Furthermore, the fluorescent OCNQDs are applied for live cell imaging and Fe³⁺ ions detecting in living cells with low cytotoxicity, good biocompatibility, and high permeability. Overall, the fluorescent OCNQDs fabricated in this work can be promising candidates for a range of chemical sensors and bioimaging applications.