Surface charge modification of wild-type Cowpea mosaic virus, a plant virus, is sufficient to promote the templated mineralization of metal and metal oxide. Surface negative charge is increased by the chemical introduction of succinamate on surface lysine groups. The cobalt and iron oxide templated nanoparticles subsequently obtained are monodisperse with a diameter of ca. 32 nm. Further, the iron oxide-CPMV nanoparticles can be readily decorated with thiol-containing molecules.