Thermogenesis detection of single living cells via quantum dots

Cellular endocytotic quantum dots (QDs) have been successfully used as thermometers to sense temperature variations inside single living cells. Temperature changes have been detected remotely through optical readout. We showed the increased extracellular calcium concentration can trigger the thermogenesis of NIH/3T3 cells and therefore elevated the cellular temperature about 1.5 °C. This technique has the potential as nanoscale thermometers for intracellular temperature measurements using non-contact, far field optical instruments with combination of both diffraction-limited spatial resolution at about 700 nm and sampling-rate-limited temporal resolution at about 30-100 ms.