The Application of Supramolecular Nanostamping (SuNS) to the Replication of DNA Nanoarrays

The present spot size for DNA microarrays is on the order of micrometers. However, there is a need for smaller arrays to allow the detection of smaller volumes of analytes. Although, SPM-based techniques are capable of fabricating nanoscale bio-arrays, such fabrication methods are serial in nature and consequently slow and expensive. A recently introduced method, Supramolecular Nanostamping (SuNS) can overcome this problem by replicating DNA microarrays. In SuNS, a master (i.e. a DNA microarray made of DNA features immobilized onto a surface) is hybridized with its complementary DNA molecules terminated with `sticky' end groups. A secondary surface is then placed onto the hybridized master to allow for bond formation with the `sticky ends' of the complementary DNA. Afterwards, the master and the secondary surface are separated using heat or mechanical forces effectively achieving a replica of the original DNA array. Here, we demonstrate the application of SuNS to DNA nanoarrays proving that SuNS can reproduce DNA arrays with features as small as 14 $\pm $ 2 nm spaced 77 $\pm $ 10 nm. Moreover, we show that hybridization of these nanoarrays can be detected using AFM in a simple and scaleable way that does not require labeling of the DNA strands.