The surface of tobacco mosaic virus (TMV) is densely coated by quaternary ammonium-modified gold nanoparticles. By dropping gold nanoparticle dispersions onto TMV pre-cast substrates ("after-staining method"), nanoparticles are spontaneously adsorbed on TMVs. The adsorbed nanoparticles were fused to form semi-continuous structures. This observation indicates the possibility of preparing 1-D arrays from wide variety of nanosized materials, by using TMV tubules as templates.