http://www.ncbi.nlm.nih.gov/pubmed/20400967 (Any fulltext)
Ackermann, D., Schmidt, T. L., Hannam, J. S., Purohit, C. S., Heckel, A., & Famulok, M. (2010). A double-stranded DNA rotaxane. Nature Nanotechnology, 5(6), 436-42. doi:10.1038/nnano.2010.65.