The insoluble Prussian blue pigment was dispersed into greener solvents as surface-charged nanoparticles via their surface modification using various alkylamines. The nanoparticles bore negative zeta potentials originated from the surface [Fe-III-OH]- moieties and their Surrounding protonated alkylamines, [R-NH3]+, and their dispersible nature into solvents was controllable depending on the alkyl-chain lengths.