The growth of manganese oxide decorated iron oxide nanoflowers atop polyethylenimine functionalized carbon felt via surface-bound iron particle seeds is explored with and without the aid of a surfactant ligand in a one-pot aqueous solution for the first time. Widespread, uniquely shaped, rough nanocrystal growth is shown to develop on the hydrophilic surface of functionalized carbon felt fibers and the growth is achieved using a seed, initiator, reducer, and ligand mixture. The structure of the iron-manganese oxide nanoflowers are optically examined, and the anodic viability of the modified carbon felt in microbial fuel cells is determined through analysis of the stimulation and maturation of yeast via electrochemical characterization. The developmental growth of the iron-manganese oxide nanoparticles with the beneficial addition of the surfactant ligand, sodium dodecylbenzenesulfonate, and different ratios of iron to manganese are observed to have an effect on the condition of yeast biofilm inhabitancy, viability, and the resulting electrochemical behaviour. The best power density of 5.8 ± 0.61 W m−2 is achieved when utilizing this surfactant mediated iron-manganese oxide nanoparticle growth technique to the microbial fuel cell anode.