Investigation of Intracellular Thermogenesis Dynamics using Mitochondria-Targeted Nanodiamond Quantum Thermometry

Intracellular thermometry techniques provide valuable information into biological processes by detecting temperature variations within specific organelles under different physiological conditions. However, miniaturizing biocompatible thermometers to submicrometer sizes and attaching them to organelles pose significant challenges. In this study, we present a novel approach utilizing organelle-targeting nanodiamond quantum thermometry, using nitrogen-vacancy (NV) color centers, to monitor temperature changes during ATP generation within living human skin fibroblast cells. To enable this monitoring, we developed a microscopy system that integrates a coplanar waveguide-incubating chamber and a real-time particle tracking system, facilitating the tracking of nanodiamonds within cells while simultaneously measuring temperature. Using this system, we induced temperature rise based on the thermogenic response by inhibiting ATP synthesis, and measured the resulting changes in temperature within mitochondria, nucleus, and membrane. Our technique can achieve spatially resolved temperature measurements related to mitochondrial thermodynamic and gain insights into the distinct thermodynamic properties in specific organelles within cells.