posted on 2021-04-21, 13:17authored byYingke Wu, Md Noor A Alam, Priyadharshini Balasubramanian, Anna Ermakova, Stephan Fischer, Holger Barth, Manfred Wagner, Marco Raabe, Fedor Jelezko, Tanja Weil
Temperature is an
essential parameter in all biological systems,
but information about the actual temperature in living cells is limited.
Especially, in photothermal therapy, local intracellular temperature
changes induce cell death but the local temperature gradients are
not known. Highly sensitive nanothermometers would be required to
measure and report local temperature changes independent of the intracellular
environment, including pH or ions. Fluorescent nanodiamonds (ND) enable
temperature sensing at the nanoscale independent of external conditions.
Herein, we prepare ND nanothermometers coated with a nanogel shell
and the photothermal agent indocyanine green serves as a heat generator
and sensor. Upon irradiation, programmed cell death was induced in
cancer cells with high spatial control. In parallel, the increase
in local temperature was recorded by the ND nanothermometers. This
approach represents a great step forward to record local temperature
changes in different cellular environments inside cells and correlate
these with thermal biology.