Nafion sub-micro particles doped with methyl viologen (MV2+) are synthesized using the re-precipitation method and characterized by scanning electron microscopy and UV-Vis spectroscopy. The electrochemical behavior of MV2+ incorporated into Nafion particles was investigated at both the ensemble and single particle levels. The charge transferred to single MV-Nafion particles was observed using the nano-impact method and shown to be quantitative. Finally, the charge transferred via individual MV-Nafion particle was substantially enhanced in the presence of permanganate. The mechanism of the catalytic nano-impact reaction of mediated permanganate reduction by single MV-Nafion particle is revealed as proceeding via MV+˙ reduced from MV2+ incorporated in Nafion particles through one electron transfer followed by the reduction of permanganate.