Before revision:  To our surprise, a unique entropy fluctuation interplay of the denaturation bubbles is revealed, apparent in a two-stage transition profile. The dynamic dissipation at resonance , which we record, faithfully captures the base-pair binding-unbinding energy landscape, revealing the singular entropy fluctuation characteristic. We attribute the characteristic to the onset of an energy fluctuation scale observable only at the small volume scales employed. The fluctuations apparently favor entropy ordering over disordering at biologically relevant T< 42C in a non-equilibrium transition pathway.
After revision:  We exploit nanomechanical resonance to measure the NE energy exchanges through dissipation, revealing a crucial pre-melting transition at T~ 42C in a non-equilibrium transition pathway.