Dual-excitation decoding multiparameter-based ratiometric luminescence thermometry: a new strategy toward reliable and accurate thermal sensing

Abstract

Luminescence thermometry can perform noninvasive thermal sensing with high spatial resolution and fast response, emerging as an exciting field of research due to its promising applications in biomedicine. Nevertheless, because of the interaction between light and complex tissues, the reliability and the accuracy of this technique suffer serious interference, which significantly restricts its practical utilization. Here, a strategy to implement effective luminescence nanothermometry is preliminarily proposed by employing the different thermal responses between Yb 3 + → Nd 3 + and Nd 3 + → Yb 3 + energy transfer processes. Different from the traditional ratiometric sensing method, where two luminescence intensities are used as the thermal response parameters, we use two intensity ratios between Yb 3 + and Nd 3 + near-IR emissions that are obtained under dual excitation as the detecting and reference signals to perform temperature measurement. This multiparameter-based, self-reference thermometry technique, as we define it, exhibits excellent immunity to the influences arising from the fluctuation and loss of pumping sources as well as the luminescence attenuation in media. High thermal sensitivity ( ∼ 2.2 % K − 1 ) and good resolution ( ∼ 0.35 ° C ) are successfully achieved here, accompanied by a measurement error of ∼ 1.1 ° C in a biological environment test, while large errors are observed based on the traditional ratiometric approach ( ∼ 8.9 ° C , ∼ 23.2 ° C ). We believe the viewpoint in this work could boost luminescence thermometry and provide an ingenious route toward high-performance thermal sensing for biological systems.