Comparison of the sensitivity as optical temperature sensor of nano-perovskite doped with Nd3+ ions in the first and second biological windows

Abstract

The temperature evolution of the infrared luminescence of yttrium orthoaluminate nano-perovskite, doped with 1.0mol% of Nd3+ ions, was analyzed in order to check its viability as optical thermal sensor in the well-known “near infrared biological windows” of the human tissue. For this purpose, the dependences of the emission bands of the (2H9/2, 4F5/2), 4F3/2→4I9/2 transitions from RT up to 610K and the emission band of the 4F3/2→4I13/2 transition from RT up to 370K for the first and second biological windows respectively, were measured and calibrated as functions of the temperature. From the calibration procedure of the optical sensor in the first biological window, the maximum value of the relative sensitivity was obtained and compared with others Nd-based optical sensors of the literature, showing a notable sensitivity. In addition, the relative sensitivity in the second biological window at RT was almost twice higher than the obtained one in the first biological window at the same temperature, showing a high sensitivity of the nano-perovskite in the biophysical temperature range (30–45°C). Moreover, it has been studied among the emission sub-tissue penetration depth through a phantom tissue, taking advantage of the emission of Nd3+ in the second biological window. These results show the potential use of the yttrium orthoaluminate nano-perovskite doped with 1.0mol% of Nd+3 for both sub-tissue luminescence imaging and luminescence-based thermal sensing