Sensing DNA - DNA as nanosensor: a perspective towards nanobiotechnology
  Based on modern single molecule techniques, we devise a number of possible experimental setups to probe local properties of DNA such as the presence of DNA-knots, loops or folds, or to obtain information on the DNA-sequence. Similarly, DNA may be used as a local sensor. Employing single molecule fluorescence methods, we propose to make use of the physics of DNA denaturation nanoregions to find out about the solvent conditions such as ionic strength, presence of binding proteins, etc. By measuring dynamical quantities in particular, rather sensitive nanoprobes may be constructed with contemporary instruments. 
Ralf Metzler and Tobias Ambjoernsson, (NORDITA, Copenhagen)