Visible and Near-Infrared, Multiparametric, Ultrasensitive Nanothermometer Based on Dual-Emission Colloidal Quantum Dots

Dual-emission nanothermometers with the capability of precise measurement combined with high spatial resolution at the micro- and nanoscale could represent a powerful tool in several areas of technology such as microelectronics, microscale optics, photonics, microfluidics, and biomedical engineering. However, most such nanothermometers reported so far exhibit two distinct emissions located within the visible spectrum region, which limits their application potential. Here we reported a visible and near-infrared (NIR) dual-emission nanothermometer based on PbS/CdS/CdSe core/barrier/shell quantum dots (QDs). The ratiometric response of the two isolated photoluminescence (PL) peak integrated areas located at around 670 and 910 nm (corresponding to CdSe and PbS in core/barrier/shell structure, respectively) are found to be markedly temperature-dependent in the 180-300 K range with a thermal sensitivity of 1.22% K-1. In addition, the lifetime (PbS and CdSe) and PL peak shifts (PbS) exhibit a linear dependence on temperature. Multiple independent estimates of temperature could facilitate self-calibrations and enhance the accuracy of measurements. Our results evidence the great potential of visible and NIR luminescence nanothermometers based on dual-emission PbS/CdS/CdSe QDs for several technologies.