Ratiometric Temperature Sensing with Semiconducting Polymer Dots

Abstract

This communication describes ultra-bright single-nanoparticle ratiometric temperature sensors based on semiconducting polymer dots (Pdots). We attached the temperature sensitive dye—Rhodamine B (RhB), whose emission intensity decreases with increasing temperature—within the matrix of Pdots. The as-prepared Pdot-RhB nanoparticle showed excellent temperature sensitivity and high brightness because it took advantage of the light harvesting and amplified energy transfer capability of Pdots. More importantly, the Pdot-RhB nanoparticle showed ratiometric temperature sensing under a single wavelength excitation and has a linear temperature sensing range that matches well with the physiologically relevant temperatures. We employed Pdot-RhB for measuring intracellular temperatures in a live-cell imaging mode. The exceptional brightness of Pdot-RhB allows this nanoscale temperature sensor to be used also as a fluorescent probe for cellular imaging.

Remote Hyperthermia, Drug Delivery and Thermometry: The Multifunctional Platform Provided by Nanoparticles

“…Actually, Eq (4) describes quite well the behaviour of nanothermometers based on II-VI semiconductor structures and polymeric-based semiconductors, which were reported to achieve temperature measurement accuracy of 0.02 [15] and 1°C [19], respectively. Alternatively, optically-active moieties supported onto nanosized structures show a monotonic increase of the integrated emission intensity as the temperature increases.…”

“…Nanoprobes allowing remote temperature-sensing using optical or magnetic properties are among the most promising directions nowadays. Most of the optical-based nanothermometers use the light-emitting intensity [15][16][17][18][19][20][21][22][23], light-emitting peak shift [24][25][26], or lifetime decay of a suitable optical band as the thermometric property [27][28][29][30]. As far as the clinical use is concerned the drawbacks of the actual optical-based nanothermometers rely on biocompatibility (usual semiconductor-based core nanoprobes or dye-based shell moieties are toxic), robustness (typical bleaching of organic-based shell moieties) or temperature accuracy (no better than 0.3°C nowadays), or even combination of these factors.…”

Cell Thermoregulation: Problems, Advances and Perspectives

“…Among these emerging thermometers, which are based on lanthanide nanoparticles (Vetrone et a., 2010;Peng et al, 2010;Brites et al, 2010;Fisher et al, 2011), dye-coated nanoparticles (Huang et al, 2010), quantum dots (Yang et al, 2010), semiconducting polymer dots (Ye et al, 2011), temperature-responsive polymers (Chen & Chen, 2011;Gota et al, 2009) and a fluorescent nanogel thermometer (FNT) by combining a thermo-responsive polymer with a water-sensitive fluorophore (Okabe et al, 2012). To the point, the last is the only thermometer that allows the mapping of intracellular temperatures due to its ability to diffuse throughout living cells and its sensitivity to temperature.…”

Conjugated Polymer Nanoparticles for Label‐Free and Bioconjugate‐Recognized DNA Sensing in Serum

“…Besides the extensive applications in cellular imaging and immunofluorescent labeling,19, 20, 21, 22 CPNs have also been verified to be a promising fluorescent probe for metal ion detection,23 intracellular pH value,24 and temperature sensing 25. Among these various existing applications, few CPNs have been used in DNA‐related sensors, thus seriously restricting the comprehensive applications of the CPNs.…”