Combined-dynamic mode “dip-pen” nanolithography and physically nanopatterning along single DNA molecules

Atomic force micriscope (AFM)-based dip-pen nanolithography (DPN) is an emerging approach for constructing nanostructures on material surfaces such as gold, silicon and silicon oxide. Although DPN is a powerful technique, it has not shown its ability of direct-writing and patterning of nanostructures on surfaces of soft materials, for example biomacromolecules. Direct depositing on soft surfaces becomes possible with the introduction of a combined-dynamic mode DPN rather than mostly used contact mode DPN or tapping mode DPN. In this report, the combined dynamic mode DPN is used for direct depositing protein ink on DNA molecules at the nanometer scale.     

Mechanism and development of dip-pen nanolithography （DPN）

Dip-pen nanolithography is a new scanning probe lithography （SPL） technique based on atomic force microscopy （AFM） , and now has made a great progress. The process of dip-pen lithography involves the adsorption of ink molecules on AFM tip, the formation of water meniscus, the transport of ink molecules, and diffusion of ink molecules on the substrate. More factors such as temperature, humidity, tip, scanning speed and so on will influence the process of dip-pen lithography. The paper analyzes in detail the mechanism of this technique, introduces synthetically the latest development, including electrochemical DPN, more-mode DPN, multiple DPN, multi-probe array DPN and so on. Finally, the paper describes the characteristics and the application of DPN.