Harnessing DNA for nanothermometry

Abstract

Temperature measurement at the nano-scale has brought insight to a wide arrayof research interests in modern chemis-try, physics, and biology. These measure-ments have been enabled by the adventof nanothermometers, which relay nano-scale temperature information throughthe analysis of their intrinsic photo-physical behavior. In the past decade, several nanothermometers have beendeveloped including dyes, nanodiamonds, fluorescent proteins, nucleotides,and nanoparticles. However, temperature measurement using intact DNA hasnot yet been achieved. Here, we present a method to study the temperaturesensitivity of the DNA molecule within a physiologic temperature range whencomplexed with fluorescent dye. We theoretically and experimentally reportthe temperature sensitivity of the DNA-Hoechst 33342 complex in differentsizes of double-stranded oligonucleotides and plasmids, showing its potentialuse as a nanothermometer. These findings allow for extending the thermalstudy of DNA to several research fields including DNA nanotechnology, opti-cal tweezers, and DNA nanoparticles.