A Sensitive and Reliable Organic Fluorescent Nanothermometer for Noninvasive Temperature Sensing

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Accurate subcellular temperature sensing is vital for understanding biological processes.
• Developing sensitive and reliable organic fluorescent nanothermometers presents significant challenges.

Purpose of the Study:

• To fabricate and characterize a novel organic fluorescent nanothermometer for precise temperature sensing.
• To evaluate its application in biological systems, particularly bacterial biofilms.

Main Methods:

• Synthesis of a dual-responsive organic luminogen.
• Encapsulation within natural saturated fatty acids to create a temperature-sensitive matrix.
• Formulation into colloidally dispersed nanoparticles using in situ surface polymerization and nanoprecipitation.

Main Results:

• The zwitterionic nanothermometer demonstrated sensitive, reversible, and multiparametric responses around physiological temperature (37 °C).
• High relative thermal sensitivities were achieved using spectral position, fluorescence intensity, and fluorescence lifetime (up to 17.72% °C⁻¹).
• Successful multimodal temperature sensing of bacterial biofilms was demonstrated.

Conclusions:

• The developed organic fluorescent nanothermometer offers superior sensitivity and reliability for subcellular temperature measurements.
• Its ability to perform multimodal sensing and potential for cellular uptake makes it promising for biological thermal behavior studies.