Ultrafast detectability of mitochondrial temperature spikes by fluorescent thermometers

Determine whether fluorescent molecular thermometers used for mitochondrial temperature measurements can sense rapid, localized temperature spikes on picosecond to nanosecond timescales caused by ion translocation events across the inner mitochondrial membrane.

Background

The paper proposes that proteins embedded in the inner mitochondrial membrane act as ratchet engines and that dehydration–translocation–rehydration cycles of ions generate ultrashort, localized temperature spikes. While fluorescence thermometry has provided evidence for elevated mitochondrial temperatures, typical experimental setups have millisecond temporal resolution, which may be insufficient to capture picosecond–nanosecond spikes predicted by the model.

The authors suggest that computational approaches (e.g., TD-DFT and ab initio molecular dynamics) could probe whether fluorophores exhibit fast enough photophysical responses to register such transient heating, but they explicitly note that it is presently unknown whether commonly used molecular thermometers can detect temperature changes on these ultrafast timescales.