Nanocopying of individual DNA strands and formation of the corresponding surface pattern of titania nanotube

Titania nanotube was prepared by nanocopying of the individual DNA double strand as template. DNA was first spread on a solid substrate, and its molecular surface was coated with an ultrathin titania layer by 3 cycles of the surface sol-gel process. Fluorescence microscopic images before and after titania coating of the DNA/YOYO-1 complex were essentially identical, showing that the titania coating did not change the chemical properties of the complex. Titania coating effectively prohibited chemical degradation of titania-coated DNA with DNase I and physically separated the DNA strand from the surrounding environment with an ultrathin titania barrier. The morphology of the DNA strand was preserved, as confirmed by microscopic and spectroscopic observations. The presence of the hollow (tubular) structure was confirmed by a silver staining experiment coupled with scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy (STEM-EDX) analysis. The present finding shows the effectiveness of nanocopying of the individual DNA strand.