Thermal Mapping with Quantum Dots in a Living Cell

A photothermal experimental system for intracellular thermal mapping is presented, which makes the use of aqueous CdTe/CdS/ZnS quantum dots as the thermal sensors and allows the measurement of temperatures in living cells embedded with the QDs via temperature-dependent photoluminescence (PL). Measured data show that the QDs synthesized in our laboratory have a thermal-PL sensitivity of 0.16nm/ degrees C . An uptake of QDs into living cells is made accomplished by the liposome transfection method. The intracellular temperature measuring capabilities of the system is demonstrated by the use of ionomycin calcium ions as a cellular thermogenesis accelerator to autonomously induce temperature changes in living cells. By adjusting the optical components in the measurement system, the QDs can be located and their PL emission variation as a function of temperature in a living cell was measured.