Design, Synthesis And Application Of Rare Earth Functionalized Nano-thermometer

In recent years,the development of nanotechnology has greatly promoted the development of nanoparticle-based treatment methods.Nanotechnology-based nanotherapeutic technologies such as photodynamic therapy?PDT?,photothermal therapy?PTT?,and acoustic power therapy?SDT?have been developed.Among them,photothermal therapy is a promising nanotherapeutic technology.PTT employs photo-absorbing agents to generate heat from light,leading to thermal ablation of cancer cells and the subsequent cell death.The precise sensing of temperature is an important factor to promote the efficacy of PTT.However,the current method to monitor the temperature during PTT is to use a thermographic imaging method.Infrared thermography,which is based on the principle of blackbody radiation,is generally reflected by the temperature of the surface of the objects.Therefore,it is important to find a new type of in-situ temperature sensor that can apply in the process of PTT and improve the efficacy of PTT.Luminescence-based thermometry technique has been proposed as a promising alternative because of the fast response,high sensitivity,excellent spatial resolution,and ability to function even in strong electromagnetic fields and intracellular measurements.Because of the electronic configuration of rare-earth elements,the f-f transition of rare-earth elements is Laporte forbidden,thus,they often possess many optical properties.For instance,rare-earth elements have a large Stokes shift,the emissions cover a wide range from ultraviolet to visible and long fluorescence lifetime.Selecting the appropriate rare-earth ions which can achieve dual mode temperature online feedback by using fluorescence intensity and fluorescence lifetime during the process of PTT is expecting.In this paper,the rare-earth elements and photothermal conversion materials are combined to design intelligent heater-thermometer integrated nanoplatforms,which can realize real-time temperature feedback during the process of PTT.This paper is mainly divided into the following three parts:Chapter 1:briefly describes the development status of thermometer based on fluorescence technology and the application of rare-earth elements in fluorescent thermometers.Chapter 2:a two-photon?-diketone ligand?4,4,4-trifluoro-1-?9-hexyloxazol-3-yl?-1,3-butanedione?HTHA??and Fe?III?/tannic acid complex?Fe/TA?were synthesized and functional assembled into an Eu?III?-based nanoscale metal-organic framework?Eu-NMOF?.Then,a multifunction nanoprobe THA@Eu-NMOF@Fe/TA was synthesized.Eu³⁺gives the material the ability to detect temperature by using fluorescence intensity and fluorescence lifetime.Because of the photothermal function of Fe/TA,THA@Eu-NMOF@Fe/TA can convert light energy to heat.Thus,this functionalized material can achieve temperature sensing and optical heating in a single beam of near-infrared?NIR?light.Because of the photothermal and antibacterial properties of Fe/TA,the probe also has the ability to kill bacteria.Chapter 3:the dual-mode temperature response nanoprobe CDs-Tb-TMPDPA,composed of a two-photon ligand?4-?2,4,6-Trimethoxyphenyl?-pyridine-2,6-dicarboxylic acid?TMPDPA??sensitized Tb?III?complex as a temperature sensitive unit and the carbon dots?CDs?with surface-rich ligands and photothermal capacity as nanocarriers,has been designed and synthesized.Under365 nm light irradiation,upon the increase of the temperature,the luminescence intensity from the Tb³⁺is decreased,while that from the carbon dots?CDs?remains unchanged,which makes it possible for the luminescence intensity ratio detection of temperature.The nanoprobe exhibits good temperature sensing properties in the range of 20-60?with a relative sensitivity of up to2.35%·?^-1.In addition,the nanoprobe also displays a significant change in emission lifetime accompanied by the temperature variation.Under 660 nm light irradiation,upon the increase of the temperature,the fluorescence lifetime of Tb³⁺is decreased from 253?s to 127?s with a maximum sensitivity of 2.45%·?^-1.Due to the excellent photothermal conversion capability of CDs,it can also be used as an antibacterial agent.The research work provides a new idea for the design and synthesis of a new type of heater-nanothermometer intelligent integrated fluorescent nanoprobe.