Boosting the sensitivity of Nd(3+)-based luminescent nanothermometers

• Published in: Nanoscale Vol. 7; no. 41; p. 17261
• Main Authors: Balabhadra, Sangeetha, Debasu, Mengistie L, Brites, Carlos D S, Nunes, Luís A O, Malta, Oscar L, Rocha, João, Bettinelli, Marco, Carlos, Luís D
• Format: Journal Article
• Language: English
• Published: England 07-11-2015
• Subjects: Luminescent Measurements - methods; Nanoparticles - chemistry; Neodymium - chemistry; Sensitivity and Specificity; Thermometers
• ISSN: 2040-3372
• DOI: 10.1039/c5nr05631d

Luminescence thermal sensing and deep-tissue imaging using nanomaterials operating within the first biological window (ca. 700-980 nm) are of great interest, prompted by the ever-growing demands in the fields of nanotechnology and nanomedicine. Here, we show that (Gd1-xNdx)2O3 (x = 0.009, 0.024 and 0.049) nanorods exhibit one of the highest thermal sensitivity and temperature uncertainty reported so far (1.75 ± 0.04% K(-1) and 0.14 ± 0.05 K, respectively) for a nanothermometer operating in the first transparent near infrared window at temperatures in the physiological range. This sensitivity value is achieved using a common R928 photomultiplier tube that allows defining the thermometric parameter as the integrated intensity ratio between the (4)F5/2 → (4)I9/2 and (4)F3/2 → (4)I9/2 transitions (with an energy difference between the barycentres of the two transitions >1000 cm(-1)). Moreover, the measured sensitivity is one order of magnitude higher than the values reported so far for Nd(3+)-based nanothermometers enlarging, therefore, the potential of using Nd(3+) ions in luminescence thermal sensing and deep-tissue imaging.