A Dopamine Sensor Based on Pre-Concentration by Magnetic Nanoparticles

Figure 3

(a) The cyclic voltammograms obtained at the MCPE/MNP in 0.1 M PBS containing 0.1 M NaClO₄ in the presence of 0.5 mM [Fe(CN)₆]^3−/4− at different pH. Outer to inner; pH 2.5, 3.0, 4.1, 4.6, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, and 9.5. (b) Faradaic current titration curve for the MCPE/MNP (solid line) and its first derivative (dotted line), normalized 𝑖_p is (𝑖_p(max)−𝑖_p)/𝑖_p(max).

(a)

(b)