Synergy of Resonance Attenuation and Thermal Quenching to Enhance Temperature Sensitivity of Fluorescent Probes for Investigating Cellular Glucose Metabolism-Induced Thermogenesis.

Accurate measurement of cellular temperature and a deep understanding of thermogenesis are essential for unraveling the complexity of cellular metabolism and for the early diagnosis and treatment of diseases. Herein, we employ a unique dual-signal attenuation strategy to construct a thermoresponsive fluorescent probe Au@SiO2-NIPAM-Eu (ASNE). The synergistic attenuation of the ASNE fluorescence signal is triggered by an increase in ambient temperature: first, the intrinsic fluorescence of Eu3+ decreases; second, the temperature-sensitive polymer is induced to undergo phase transitions from dispersed chains to compact spheres, resulting in proximity between the Eu3+ emitters and Au nanoparticles and attenuating fluorescence through localized surface plasmon resonance (LSPR) effects. The sensitivity of temperature measurement is greatly enhanced by this dual reduction effect, enabling ASNE to be successfully applied in temperature imaging of living cells. Combined with alterations in the levels of glycolysis-related indicators, it further revealed differences in glycolytic characteristics between normal and cancer cells. Cancer cells rely on aerobic glycolysis, exhibiting low energy efficiency, with most of the energy lost as heat. Normal cells primarily undergo aerobic respiration, storing most of the energy in ATP. Under glucose conditions, cancer cells exhibit a temperature increase of 0.53 °C more than normal cells in 25 min. After the addition of FCCP, oxidative phosphorylation is inhibited in normal cells, and the temperature increase is 1.84 °C higher than in cancer cells at 25 min. This approach holds significant promise for advancing cellular temperature sensors and provides a foundation for future investigations into metabolic mechanisms and early cancer diagnosis.