A simple yet effective AIE-based fluorescent nano-thermometer for temperature mapping in living cells using fluorescence lifetime imaging microscopy

Abstract

We designed and synthesized a novel nano-thermometer using aggregation-induced-emission (AIE) dye as the reporter and household butter as the matrix. This temperature nanosensor showed decreased fluorescence intensities (similar to 2%/degrees C) and shorter fluorescence lifetimes (similar to 0.11 ns/degrees C) upon increasing the environmental temperature in the physiological temperature range. Such fluorescence responses were reversible and independent of the environmental pH and ionic strength. The application of these nano-thermometers in temperature sensing in living cells using fluorescence lifetime imaging microscopy (FLIM) was also demonstrated. To the best of our knowledge, this is the first example of AIE-based nano-thermometer for temperature sensing in living cells. This work also provides us with a simple and low-cost method for rapid fabrication of an effective nanosensor based on AIE mechanism.