Palladium and silver nanoparticles (NPs) anchored at the outer surface of ferritin form stable suspension of non-coated particles that possess several catalytic and enzymomimetic activities. These activities are strongly affected by detergents that significantly influence the reaction efficiency and specificity. Reductive dehalogenation of various azo dye substrates shows strong differences in reactivity for each substrate-detergent pair. Reductive dehalogenation is negatively influenced by cationic detergents while catalytic depropargylation is severely impaired by polyethylene oxide containing detergents that is an important finding in respect to potential biorthogonal applications. Moreover, Suzuki-Miyaura reaction is promoted by polyethylene oxide containing detergents but some of them also facilitate dehalogenation. Enzymomimetic peroxidase activity of silver NPs can be detected only in presence of sodium dodecyl sulfate (SDS) while peroxidase activity of palladium NPs is enhanced by SDS and sodium deoxycholate.