Highly Fluorescent Nitrogen-Doped Graphene Quantum Dots’ Synthesis and Their Applications as Fe(III) Ions Sensor

Figure 9

(a) Fluorescence probe solution with different metal ions irradiated by 365nm Ultraviolet Lamp; (b) drop coating of different metal ions on paper-based sensors; (c) fluorescence changes of N-GQDs in the presence of different metal ions (including Cu²⁺, Ag⁺, Co²⁺, Fe³⁺, Ba²⁺, Al³⁺, Mn²⁺, Fe²⁺, K⁺, Na⁺, and Zn²⁺ ions).

(a)

(b)

(c)