Immobilization and characterization of ferritin on gold electrode

Properties of ferritin, immobilized on dithiobis (N-succinimydyl propionate) (DTSP)-covered gold electrode, in 3-morpholino propanesulfonic acid buffer were investigated by AFM and FE-SEM. Electrochemical properties the ferritin was measured by a cyclic volatammetry. When the potentials of 0.2, 0.34, and 1.0V vs. Ag/AgCl were applied for 15h for the ferritin immobilization, the electrode potential of Fe(II)/Fe(III) in ferritin changed to negative values. Negative electrode potential shift of Fe(II)/Fe(III) in ferritin with respect to the applied potential could be attributed to the stabilized ferritin on DTSP-covered gold electrode. From AFM and SEM images, it was proven that ferritins fixed at below 0.34V were clusters in several micrometer and those fixed at higher applied potential than OCV were finely distributed particles in several tens of nanometer.