Dual-Emission Fluorescent Silicon Nanoparticles-Based Nanothermometer for Ratiometric Detection of Intracellular Temperature in Living Cells
In this article, we present a kind of dual-emission fluorescent nanothermometer, which is made of europium (Eu3+)-doped silicon nanoparticles (Eu@SiNPs), allowing the detection of intracellular temperature in living cells with high accuracy. In particular, the presented SiNPs-based thermometer features dual-emission fluorescence (blue (455 nm) and red (620 nm) emission), negligible toxicity (cell viability of treated cells remains above 90% during 24-h treatment) and robust photostability in living cells (e.g., preserving >90% of fluorescence intensity after 45 min continuous UV irradiation). More significantly, the fluorescence intensity of Eu@SiNPs exhibits a linear ratiometric temperature response in a broad range from 25 to 70 °C. Taking advantage of these attractive merits, such Eu@SiNPs-based nanothermometer is able to accurately (~4.5 % change/°C) determine dynamic changes of intracellular temperature in quantitative and long-term (e.g., 30 min) manners.