title: Structural insights into magnetic clusters grown inside virus capsids.
abstract: Magnetic nanoparticles have multiple applications in materials science. In particular, virus capsids have been suggested as promising templates for building up nanometric-sized magnetic clusters by taking advantage of their inner cavity as a nanoreactor. In this study we investigate the magnetization of individual cobalt-filled cowpea mosaic virus empty virus-like particles using atomic force microscopy. We also combine the analysis of the effects of dehydration on the structure of virus particles with a comparison of their magnetic signal to that provided by commercially available magnetic nanoparticles of similar size. These two approaches allow the evaluation of the structure of the metallic cluster grown inside the virus capsid. We conclude that, rather than forming solid clusters, cobalt inside viruses forms a discontinuous structure that does not completely fill the virus cavity and reaches about 10% of its volume.
authors.affiliation: Departamento de Física de la Materia Condensada y Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , 28049 Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Jaafar
authors.forename: A A A
authors.initials: AA
authors.lastname: Aljabali
authors.forename: I
authors.initials: I
authors.lastname: Berlanga
authors.forename: R
authors.initials: R
authors.lastname: Mas-Ballesté
authors.forename: P
authors.initials: P
authors.lastname: Saxena
authors.forename: S
authors.initials: S
authors.lastname: Warren
authors.forename: G P
authors.initials: GP
authors.lastname: Lomonossoff
authors.forename: D J
authors.initials: DJ
authors.lastname: Evans
authors.forename: P J
authors.initials: PJ
authors.lastname: de Pablo
mesh_terms: D002213:Capsid / Q000737:chemistry; D036022:Capsid Proteins / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D014771:Virion / Q000737:chemistry* / Q000254:growth & development; D014780:Viruses / Q000737:chemistry* / Q000187:drug effects
chemical_list: D036022:Capsid Proteins; D058185:Magnetite Nanoparticles; D003035:Cobalt
keywords: magnetic force microscopy; magnetic nanoparticles; nanoreactors; protein cages; virus capsid