Stabilization of DNA nanostructures by photo-cross-linking

Developing methods for stabilizing DNA nanostructures is a major challenge for next-generation nanofabrication, because stable DNA nanostructures are expected to work as building materials in the bottom-up assembly of functional biomolecules and nano-electronic components. Here we show the availability of cross-linking-type photoreaction with 3-cyanovinylcarbazole nucleosides ((CNV)Ks) on DNA nanostructures. DNA double-crossover AB-staggered (DXAB) tiles including cross-linking molecules, CNVKs, self-assembled into two-dimensional (2D) periodic DNA arrays and were covalently connected by photo-cross-linking. The self-assembled DNA arrays before and after photo-cross-linking have been visualized by high-resolution, tapping mode atomic force microscopy (AFM) in buffer. The improvement of the heat tolerance of photo-cross-linked DNA arrays was confirmed by heating and visualizing the DNA nanostructures. The heat-resistant DNA arrays may expand the potential of DNA as a functional material in biotechnology and nanotechnology.