Closed nanoconstructs assembled by step-by-step ss-DNA coupling assisted by phospholipid membranes
Baldelli Bombelli F., Betti F., Gambinossi F., Caminati G., Brown T., Baglioni P., Berti D.
We report experimental evidence of the construction of closed pseudo-hexagonal DNA nanostructures grafted onto lipid membranes (supported planar bilayers or liposomes). The anchoring agent is a cholesteryl tetraethylenglycol-18-mer oligonucleotide, which recruits the complementary sequences added in a sequential fashion. A closed rather than an open nanostructure was chosen as a test for possible future applications in nanoelectronics and for the fact that a more rigid and defined structure can offer many advantages in terms of addressability and spatial control. The so-built hybrid soft nanomaterial has never been reported previously and merges the unique features offered by DNA building blocks in nanotechnology, to the characteristics of amphiphilic self-assembly, in terms of responsiveness and further hierarchical aggregation in functional arrays of nano-units. The liposomes decorated with DNA pseudo-hexagons are structurally stable for weeks and can thus be further exploited or specifically addressed. The structural features of the final nanoobjects are independent on the sequence of preparation, i.e. step-wise on the membrane or addition of preformed hexagons, up to a threshold of density on the surface or vesicle number density. © The Royal Society of Chemistry 2009.