Detection of Melamine Based on the Fluorescence Changes of Nitrogen-Doped Carbon Dots

Figure 6

(a) The fluorescence emission spectrum of the system (λ_ex = 370 nm, NCDs were diluted 5 times, Hg²⁺ = 1.2 mM, melamine = 0–10 mg/L). Inset of (a) show the graph of the peak intensity of the system. (b) A linear relationship of (F–F₀)/F₀ versus the concentration of melamine over the range 50–400 μg/L. (c) A linear relationship of (F–F₀)/F₀ versus the concentration of melamine over the range 800–2500 μg/L (F₀ and F are the fluorescence intensities of the system at 440 nm in the absence and presence of melamine, respectively).

(a)

(b)

(c)