Scientists Create Nano-Thermometer That Can Take Temps Inside Cells

When we are feeling sick, one of the first things that we typically do is take our temperature with a thermometer. Scientists at Rice University have now created a fluorescent nano-thermometer that's able to take the temperature inside of cells. The scientist used the light-emitting properties of particular molecules to create the thermometer.

The work was done in the lab of chemist Angel Marti, and the paper on the nano-thermometer describes the technique and how the team modified a biocompatible molecular rotor known as boron dipyrromethene (BIODIPY) to reveal the temperature inside a single cell. The scientists say this particular molecule is ideally suited for the task.

The teams say that the fluorescence of BIODIPY lasts only a little while inside the cell with the duration depending heavily on changes in temperature and viscosity of the environment inside the cell. At high viscosity, the environment in typical cells the fluorescence lifetime depends on temperature alone.

The technique relies on the rotor according to the team. The rotor was constrained to go back and forth, like a flywheel in a watch rather than letting it rotate fully. The team measures how long the molecule stays in the excited state, which is dependent on how fast it wobbles. When the temperature increases, the rotor wobbles faster.

Scientists say that the speed of the wobble is independent of the concentration of BIODIPY molecules in the cell and of photobleaching, which is the point where the fluorescent capabilities of the molecule are destroyed. The scientists think that the technique could be useful in quantifying the effects of tumor ablation therapy where heat is used to destroy cancer cells. The technique could potentially be used to measure the presence of cancers.