As shown in Figure , the anodic peak current increases linearly with the square root of the scan rate, confirming that the mass transport of the Fc12-PF6 is under diffusion control. The diffusion coefficient of Fc12-PF6 was calculated as 2.0 ± 0.2 ´10 -8 cm 2 s -1 . These results align with the 0.2%Fc12-Br/MO. The electrochemical activity of 0.2%Fc12-PF6/MO resulted to be comparable to 0.2%Fc12-Br/MO (see SI Figure ).