Abstract

Upconversion fluorescence is the process of converting optical energy from low absorption energies to high emission energies. The upconversion (UC) materials exhibit significant advantages such as high penetration depth, low unwanted autofluorescence and light scattering from biological species at near-infrared excitation. Nowadays, UC materials are widely applied in optical applications, including solid-state lasers, temperature sensor and chemical sensors. The upconversion materials consist of low phonon host material and sensitizer-activator pair. The sensitizer and activator are often rare earth elements, where energy transfers from the sensitizer to the activator. This review describes the general picture and recent progress of lanthanide upconversion fluorescent materials along with applications in biochemical sensing and imaging. We also provide novel strategies to enhance upconversion intensity and tunable emissions with doping metal ions and core-shell structures, and to integrate magnetic properties to upconversion materials.

摘要

上转换荧光是将光能从低吸收能转换为高发射能的过程。上转换（UC）材料显示出显着的优势，例如高穿透深度，低有害的自发荧光以及在近红外激发下来自生物物种的光散射。如今，UC材料已广泛应用于光学应用，包括固态激光器，温度传感器和化学传感器。上转换材料由低声子主体材料和敏化活化剂对组成。敏化剂和活化剂通常是稀土元素，其中能量从敏化剂转移到活化剂。这篇综述描述了镧系上转换荧光材料的概况和最新进展，以及在生化传感和成像中的应用。