Red-Emitting Carbon Nanodot-Based Wide-Range Responsive Nanothermometer for Intracellular Temperature Sensing.

Precise sensing of intracellular temperature can provide plenty of information on disease-related cell states and promote the development of a diagnostic method. Fluorescence-based nanothermometers, as the "noncontact" sensors, exhibit great advantages over traditional thermometers due to the dual function of imaging and sensing at the molecular level. Herein, we report a red-emitting carbon nanodots (RCDs)-based nanothermometer for intracellular temperature sensing. Results indicate that RCDs exhibit favorable temperature-responsive fluorescence property with a good linear relationship, reversibility, and reproducibility under heating and cooling treatments in a wide range from 4 to 80 °C. Meanwhile, the RCDs possess satisfactory thermal sensitivity and temperature resolution, which are superior or comparable to the current nanothermometers. The low cytotoxicity and excellent temperature-responsive fluorescence property of RCDs have also been verified in living cell studies. Therefore, the RCDs will be a promising nanothermometer for intracellular temperature sensing in diverse areas.