Ratiometric upconversion nanothermometry with dual emission at the same wavelength decoded via a time-resolved technique

Xiaochen Qiu,Xingjun Zhu,Wei Feng,Fuyou Li,Zugen Wu,Qianwen Zhou

doi:10.1038/s41467-019-13796-w

Xiaochen Qiu, Xingjun Zhu + Show 4 more

Open Access

https://doi.org/10.1038/s41467-019-13796-w

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Journal: Nature Communications	Publication Date: Jan 7, 2020
Citations: 224	License type: open-access

Affiliation: Fudan University

Abstract

The in vivo temperature monitoring of a microenvironment is significant in biology and nanomedicine research. Luminescent nanothermometry provides a noninvasive method of detecting the temperature in vivo with high sensitivity and high response speed. However, absorption and scattering in complex tissues limit the signal penetration depth and cause errors due to variation at different locations in vivo. In order to minimize these errors and monitor temperature in vivo, in the present work, we provided a strategy to fabricate a same-wavelength dual emission ratiometric upconversion luminescence nanothermometer based on a hybrid structure composed of upconversion emissive PbS quantum dots and Tm-doped upconversion nanoparticles. The ratiometric signal composed of two upconversion emissions working at the same wavelength, but different luminescent lifetimes, were decoded via a time-resolved technique. This nanothermometer improved the temperature monitoring ability and a thermal resolution and sensitivity of ~0.5 K and ~5.6% K−1 were obtained in vivo, respectively.

Highlights

The in vivo temperature monitoring of a microenvironment is significant in biology and nanomedicine research
This nanothermometer exhibited thermal sensitivity up to 5.6% K−1 and a thermal resolution of ~0.5 K at approximately 45 oC. This dual emission ratiometric nanothermometry demonstrated good temperature measurement ability in tissue, and temperature mapping in tumor region in mice was performed on mice in vivo
In order to construct a ratiometric temperature sensor, broad wavelength (850–915 nm) excitation PbS quantum dots (QDs) with a Upconversion luminescence (UCL) emission around 810 nm were firstly synthesized using a hot injection method according to literature[43]

Summary

Introduction

The in vivo temperature monitoring of a microenvironment is significant in biology and nanomedicine research. The ratiometric signal composed of two upconversion emissions working at the same wavelength, but different luminescent lifetimes, were decoded via a time-resolved technique This nanothermometer improved the temperature monitoring ability and a thermal resolution and sensitivity of ~0.5 K and ~5.6% K−1 were obtained in vivo, respectively. On account of the in vivo heterogeneity at different locations, f (a) and f (s) are still challenging to simulate in vitro Taking all these factors into consideration, it is still difficult for different wavelength dual emission ratiometric nanothermometers to eliminate errors originating from tissue absorption and scattering in vivo. It is worth mentioning that NIR UCL emission and excitation in the biological window makes it applicable for bio-temperature monitoring in vivo This nanothermometer exhibited thermal sensitivity up to 5.6% K−1 and a thermal resolution of ~0.5 K at approximately 45 oC. This dual emission ratiometric nanothermometry demonstrated good temperature measurement ability in tissue, and temperature mapping in tumor region in mice was performed on mice in vivo

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