Seminars Archive

DNA strands as Gutenberg movable type: NanoContact Printing a technique for replicating multi-component

Abstract
The recent interest in nano-science has catalyzed research in the development of nano-fabrication techniques. New highly versatile nanolithography techniques based on scanning probe microscopes have been reported. A wide variety of organic and inorganic substrates can be patterned either by inducing localized chemical modifications of or by forming self-assembled monolayers (SAMs). Unfortunately, they all have in common the same drawback: they are extremely slow. A new versatile method (NanoContact Printing, NCP) that will allow for the self-assembly mediated stamping of nanofabricated substrates will be presented. Patterns generated by any nanofabrication technique could be used as stamps. In general this method will be based on a four-step approach: 1) A patterned SAM of single-strand-DNA terminated molecules is formed. 2) Complement DNA strands are assembled on the patterned DNA SAMs. The complement DNA is functionalized on one end (the one that is far from the substrate) with a chemical moiety able to react with a surface (e.g. thiol/gold or siloxane/glass). 3) A second substrate is brought close to the first, allowing for the formation of chemical bonds between the reactive groups on the complement DNA and the substrate surface. 4) The DNA double helices are dehybridized by mild heating (40-60 0C depending on DNA length). The two substrates are then separated. After this process the first substrate is left in its initial state and the second is a replica of the first one, exactly what is needed for a stamping technique. One of the main advantages of this method is that multiple DNA strands (each encoding different information) can be printed at the same time, thus allowing for a complex chemical pattern to be formed, much like Gutenberg movable type. The parallel printing of a pattern formed by four DNA strands will be presented.