One can take DNA suspension in alcohol and into it titanium alkoxide dissolved in alcohol may be slowly added ( the concentration to be optimized) . Slow addition of water under ice cooled condition into this will allow titanium to hydrolyze .The entire solution should be evacuated under low temperature and the residue finally washed with alcohol. The DNA ( residue)will be impregnated with titanium (IV) hydroxide which is nothing but hydrated TiO2. Proper drying under vacuum may remove the water. Try this