Figure 1.

PDA Polymerized by Our Method

(A) UV-VIS absorption spectra of produced polydopamine. Group Blank: water; Group Dop: dopamine only; Group Control: dopamine and hemin-lipid-AS1411 without K⁺ and H₂O_2; Group K⁺ (+), H₂O₂ (−): control only in the presence of K⁺; Group K+ (−), H₂O₂ (+): control only in the presence of H₂O₂; Group K⁺ (+), H₂O₂ (+): control in the presence of K⁺ and H₂O₂.

(B) TEM image of PD nanoparticles.

(C) Heatmap of UV-VIS absorption of polydopamine in various concentration of K⁺ and H₂O₂: Blank, Dop, and Control same as (A); K⁺: gradient concentration of potassium ion, high to low: 0 mM, 10 mM, 20 mM, 30 mM, 40 mM, and 50 mM with constant concentration of H₂O₂ = 500 μM; H₂O₂: gradient concentration of hydrogen peroxide, high to low: 0 μM, 50 μM, 100 μM, 200 μM, 500 μM, and 1,000 μM with constant concentration of K⁺ = 40 mM.

(D) Corresponding photograph of C, showing the color change.