Block copolymer nanotemplating of tobacco mosaic and tobacco necrosis viruses

Abstract

This paper examines the interaction between a block copolymer and a virus. A poly(styrene- b-4-vinylpyridine) block copolymer was loaded with nickel, and cast from a selective solvent mixture to form a cylindrical microstructure (PS/P4VP–Ni). The nickel ions were confined within the P4VP block of the copolymer. The binding of tobacco mosaic virus (TMV) and tobacco necrosis virus on microphase-separated PS/P4VP–Ni was examined. A staining technique was developed to simultaneously visualize virus and block copolymer structure by transmission electron microscopy. Electron microscopy revealed virus particles associated with block copolymer microphase-separated domains, even after extensive washes with Tween. In contrast, virus associated with PS/P4VP block copolymers lacking Ni were readily removed by Tween. The cylinder long axis of the microstructure was oriented using a hot press and a cooled channel die for quenching, resulting in PS/P4VP cylinders that had a strong anisotropic directional preference. When exposed to flowing solutions of TMV, the PS/P4VP–Ni surface exhibited an ability to retain TMV in a partially aligned state, when the direction of flow coincided with the long axis of the PS/P4VP–Ni cylinders. These results suggest that Coulombic interactions provide a robust means for the binding of virus particles to block copolymer surfaces.