Preparation And Properties Of Rare Earth Ions Co-doped ZnGa₂O₄:Cr Long Persistent Luminescent Nanoprobes And The Application For In Vivo Imaging

With the development of the optical probes,there are more and more demands for high-sensitivity probes.Therefore,how to design an optical probe with high sensitivity is very important.In order to enhance the sensitivity of optical probes,it is necessary to avoid the defects of photobleaching,toxicity and the auto-fluorescence by irradiated.Recently,the persistent luminescent nanoparticals?PLNPs?,especially the near-infrared?NIR?photoluminescence materials,have attracted great attentions in the field of optical probes.Due to the removal of the background noise originating from in situ excitation,the signal-to-noise ratio of NIR PLNPs could be significantly improved.However,up to now,the PLNPs are mostly synthesized by solid state reaction method,sol–gel process and combustion method,which nedd heat treatment with high temperature.Thus,the as-prepared persistent phosphors possess bulk size and poor water solubility,which limit seriuosly their applications to in vivo bioimaging.To overcome these problems,here,the NIR PLNPs?ZnGa₂O₄:Cr,Ln?have been synthesized by a hydrothermal method.The nanoparticles possess good water dispersibility and nanosize distribution?²5 nm?.Furthermore,the effect of rare earth ions on persistent luminescent properties of PLNPs is investigated in detail.The thermoluminescence?TL?method is utilized to investigate different traps induced by the co-dopdant of rare erath ions in ZnGa₂O₄:Cr.Furthermore,combined with long persistent luminescent properties,the novel long persistent luminescent mechanism could be proposed.At the same time,ZnGa₂O₄:Cr³⁺,Y³⁺nanoparticle is chose for imaging in vivo and with a high SNR.The ZnGa₂O₄:Cr³⁺,Y³⁺nanoparticle possesses incoherent excitation and afterglow properties,which can be charged by lasers.The PLNPs possess a variety of advantageous properties,such as good tunable decay kinetics and repeated excitation by low energy,which achieve a good potentiality for medical applications.