Intracellular temperature sensing by a ratiometric fluorescent polymer thermometer

Area of Science:

• Biophysics
• Cell Biology
• Materials Science

Background:

• Intracellular temperature dynamics are crucial for understanding cellular functions and biological reactions.
• Accurate real-time temperature monitoring within living cells remains a significant challenge in biological research.

Purpose of the Study:

• To develop a novel nanothermometer for ratiometric fluorescent imaging of intracellular temperature.
• To investigate the potential of polymer-based ratiometric fluorescent probes for precise nanoscale temperature sensing in biological systems.

Main Methods:

• Synthesis of ratiometric fluorescent polymers (RFPs) using living/controlled reversible addition-fragmentation transfer polymerization.
• Construction of the nanothermometer using a thermo-sensitive polymer, a polarity-sensitive dye, and a thermo-insensitive dye.
• Characterization of RFP response to temperature changes, including fluorescence intensity and ratiometric imaging in living cells.

Main Results:

• The synthesized RFPs demonstrated a temperature-dependent fluorescence 'turn-on' response.
• Increased temperature led to enhanced fluorescence intensity due to polymer self-assembly and dye interactions.
• Successful simultaneous temperature sensing and ratiometric imaging of temperature variations in living cells were achieved.

Conclusions:

• The developed polymer-based ratiometric fluorescent thermometer enables precise intracellular temperature measurement.
• This nanothermometer shows significant potential for spatio-temporal temperature sensing at the nanoscale within biological systems.
• The probe facilitates a deeper understanding of temperature-related biological processes in living cells.