Template-assisted assembly

Ouyang, M., Remy, J.S. and Szoka, F.C. (2000) Controlled template-assisted assembly of plasmid DNA into nanometric particles with high DNA concentration. Bioconjug. Chem., 11, 104-112. 

The formation of self-assembled monolayers (SAMs) on solid surfaces must be clearly distinguished from this case since a part of the spatial information required is provided by the surface. This case can be regarded as directed self-assembly of building blocks, which involves structure-directing additives, for example the solid surface. It is clearly distinct from spontaneous self-assembly and can rather be thought of being closely related to a template-assisted process. This may be rationalized by the pattern formation of a molecular layer on different surface orientations of the same material, which leads us to the concept of template-assisted assembly. 

In contrast to self-assembly or self-organization, which rely on the intrinsic properties of a system, template-assisted assembly provides a way to externally control the formation of a structure. The template contains spatial information, which is expUcitly imposed on the building blocks of a system. In a first step this can be a mild template effect, which only assists in the pattern formation. This effect is encountered, for example, in the structure formation of PTCDA on Ag(l 11) and Ag(l 10) [8]. In these cases the final structure of the overlayer is not only controlled by the mutual interaction of the PTCDA building blocks (self-assembly) but also assisted by the substrate. The different crystallographic orientation of the respective surfaces leads to the formation of either a herringbone pattern or a Hnear assembly on Ag(l 11) and Ag(l 10), respectively (Fig. 2). Similar results have been found for PTCDA on Cu(l 11) [9] and Cu(l 10) [10] as well as Au(l 11) and Au(lOO) [llj. 

Apart from the nanopattern, which can be derived by the deposition of atoms and the formation of inorganic films, a virtually unhmited number of structures can be generated by the adsorption and self-organization of large organic molecules on surfaces. It is far beyond the scope of this communication to explore the whole universe of these structures but a few cases, which have a direct application as templates, shall be covered below (see for example Fig. 24). In the Introduction the formation of ordered layers of PTCDA on metal surfaces was mentioned as an example of the template-assisted assembly of molecular layers, however, these layers have not been used as templates so far. 

Template-assisted assembly An assembly process that uses a template (molecular, micro, or macro) to help the drive the assembly to a specific outcome. 

The process described in the preceding section is a kind of template-assisted assembly of ZnO nanorods. The question is can we remove the ZnO nanorods from the HTlc template The results show that delamination of the ZnO nanorods on both sides of thin HTlc-Zn AICO3 can be brought about by thermally annealing the entire... 

Y. Yin, Y. Lu, B. Gates, and Y. Xia Template-Assisted Self Assembly A Practical Route to Complex Aggregates of Monodispersed Colloids with Well-Defined Sizes, Shapes and Structures. J. Am. Chem. Soc. 123, 8718 (2001). 

Y. Xia, Y. Yin, Y. Lu, and J. Me Lellan Template-Assisted Self-Assembly of Spherical Colloids into Complex and Controllable Structures. Adv. Funct. Mater. 13, 907 (2003). 

Kleij, A.W., Kuil, M., Tooke, D.M., Spek, A.L. and Reek, J.N.H. (2005) Template-assisted ligand encapsulation the impact of an unusual coordination geometry on a supramolecular pyridylphosphine-Zn(ii) porphyrin assembly. Inorg. Chem., 44, 7696-7698. 

Template-Assisted Self-Assembly of Colloidal Particles by Wrinkled Surfaces 87... 

Fig. 11 Template-assisted deposition of particles on wrinkled films. For successful assembly, the surface charge of the particles has to be of like sign as the surface charge of the wrinkled film to avoid adhesion of the particles towards the film surface...

Xia, Y., Yin, Y., Lu, Y. McLellan, J. Template-assisted self-assembly of spherical colloids into complex and controllable structures. Adv. Funct. Mat. 13, 907—918 (2003). 

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