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 1.0 V vs. Ag/AgCl were applied for 15 h 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 0.34 V were clusters in several micrometer and those fixed at higher applied potential than OCV were finely distributed particles in several tens of nanometer.