Diffusion-controlled currents of redox latex particles with polystyrene-core and polyallylamine-ferrocenyl shell

Suspensions of the titled latex, which contained 1.1 × 107, 3.9 × 107, 1.2 × 108 and 3.6 × 108 ferrocenyl units per particle for diameters of 0.60, 0.93, 1.32 and 2.00 μm, respectively, showed voltammetric redox peaks at 0.63/0.54 V for the ferrocenyl moieties. The peaks current were controlled by diffusion of the latex. They were smaller (by 74%, 57%, 28% and 14%) than values calculated from their concentration, the charge numbers and their diffusion coefficients. The partial ratio of the charge transfer increased with a decrease in the radii for a given analytical concentration of the ferrocenyl moiety, exhibiting the dependence on −1.5 powers of the radii of the particles. The latex was composed of the polystyrene (PS) core and the polyallylamine shell on which ferrocenyl carboxylic amide was immobilized. The two layers of the core–shell structure were identified with weight analysis, a photograph of the cross-section.