Temperature Sensing Using Fluorescent Nanothermometers

• Published in: ACS nano 2010-06, Vol.4 (6), p.3254-3258
• Main Authors: Vetrone, Fiorenzo, Naccache, Rafik, Zamarrón, Alicia, Juarranz de la Fuente, Angeles, Sanz-Rodríguez, Francisco, Martinez Maestro, Laura, Martín Rodriguez, Emma, Jaque, Daniel, García Solé, José, Capobianco, John A
• Format: Article
• Language: English
• Subjects: Equipment Design; Equipment Failure Analysis; HeLa Cells; Humans; Nanotechnology - instrumentation; Spectrometry, Fluorescence - methods; Thermometers
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn100244a

Acquiring the temperature of a single living cell is not a trivial task. In this paper, we devise a novel nanothermometer, capable of accurately determining the temperature of solutions as well as biological systems such as HeLa cancer cells. The nanothermometer is based on the temperature-sensitive fluorescence of NaYF4:Er3+,Yb3+ nanoparticles, where the intensity ratio of the green fluorescence bands of the Er3+ dopant ions (2H11/2 → 4I15/2 and 4S3/2 → 4I15/2) changes with temperature. The nanothermometers were first used to obtain thermal profiles created when heating a colloidal solution of NaYF4:Er3+,Yb3+ nanoparticles in water using a pump−probe experiment. Following incubation of the nanoparticles with HeLa cervical cancer cells and their subsequent uptake, the fluorescent nanothermometers measured the internal temperature of the living cell from 25 °C to its thermally induced death at 45 °C.