resumo
Whereas efficient and sensitive nanoheaters and nanothermometers are demanding tools, in modern bio- and nanomedicine, joining both features in a single nanoparticle still remains a real challenge, despite the recent progress achieved, Most Of it Within the last year. Here we demonstrate a successful realization of this challenge. The heating is magnetically induced, the temperature readout is optical, and the ratiometric thermometric probes are dual-emissive Eu3+/Tb3+ lanthanide complexes. The low thermometer heat capacitance (0.021 center dot K-1) and heater/thermometer resistance (1 K center dot W-1), the high temperature sensitivity (5.8%center dot K-1 at 296 K) and uncertainty (0.5 K), the physiological working temperature range (295-315 K), the readout reproducibility (>99.5%), and the fast time response (0.250 s) make the heater/thermometer nanoplatform proposed here unique. Cells were incubated with the nanoparticles, and fluorescence microscopy permits the mapping of the intracellular local temperature using the pixel-by-pixel ratio of the Eu3+/Tb3+ intensities. Time-resolved thermometry under an ac magnetic field evidences the failure of using Macroscopic thermal parameters to describe heat diffusion at the nanoscale.
palavras-chave
IRON-OXIDE NANOPARTICLES; MOLECULAR THERMOMETER; LIVING CELLS; TEMPERATURE; HYPERTHERMIA; NANOSCALE; FIELD
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Pinol, R; Brites, CDS; Bustamante, R; Martinez, A; Silva, NJO; Murillo, JL; Cases, R; Carrey, J; Estepa, C; Sosa, C; Palacio, F; Carlos, LD; Millan, A
nossos autores
Carlos Brites
Professor Auxiliar
Luís Carlos
Professor Catedrático
Nuno João Silva
Investigador Principalagradecimentos
This work was partially supported by the Spanish Ministry of Science and Innovation (MAT2011-259911) and in part developed in the scope of the project CICECO-Aveiro Institute of Materials (ref. FCT UID/CTM/50011/2013), financed by Portuguese funds through the FCT/MEC (RECI-CTM-CER-0336-2012, EXPL-CTM-NAN-0295-2012) and when applicable cofinanced by FEDER under the PT2020 Partnership Agreement. C.D.S.B. (SFRH/BPD/89003/2012) and N.J.O.S. acknowledge FCT for a postdoctoral grant and an IF 2013 contract, respectively. R.B. thanks ICMA-CSIC for a JAE-predoc grant. The authors would like to acknowledge the use of Servicio General de Apoyo a la Investigacion-SAI, Universidad de Zaragoza.