Synthesis and characterizations of multifunctional luminescent lanthanide doped materials

Identifier:  TDX:3338

Handle: https://hdl.handle.net/20.500.11797/TDX3338

Authors:  Nexha, Albenc

Abstract:
The development of non-contact luminescent lanthanide nanothermometers as accurate, efficient and fast diagnostic tools, attributed to their versatility, stability and narrow emission band profiles, have led to the replacement of the conventional contact thermal probes. The application of lanthanide doped nanoparticles as temperature nanosensors, excited with ultraviolet, visible or near infrared light, and the generation of emissions lying in the biological windows spectral regions: I-BW (650 nm-950 nm), II-BW (1000 nm-1350 nm), III-BW (1400 nm-2000 nm) and IV-BW (centered at 2200 nm), is notably growing due to the advantages of reduced phototoxicity and photobleaching, better image contrast and deeper penetration depths into biological tissues. Among these biological windows, the III-BW allows for deeper thermal readings within specific biological tissues, attributed to a higher penetration depth due to the reduction of absorbance and scattering when compared to the other biological windows. Nevertheless, luminescence thermometry in this spectral regime is randomly explored. Here, we synthesized and characterized luminescent Ho3+ and Tm3+ doped materials with emissions located in the III-BW for their application as luminescent thermometers and photothermal agents. We explored Ho3+ and Tm3+ doped KLu(WO4)2 and Y2O3 particles as potential self-assessed photothermal agents able to release heat and determine temperature simultaneously. For their synthesis, we adapted solvothermal (microwave-assisted and conventional autoclave) and wet-chemical (thermal decomposition and digestive ripening) methods. To conclude, we took profit of the peculiar electronic configuration and morphological characteristics of the Y2O3 nanoparticles to apply them as white light emitters and as ex-vivo antioxidant agents.