Fabrication And Properties Of Nanoprobe Based On ZnGa_1.89In_0.1O₄:Cr³⁺ Persistent Luminescence Nanoparticles

Near-infrared persistent luminescence nanoparticles can continue to generate light after stopping excitation and their emission wavelengths are in the range of the tissue transmission window（650-950 nm）,which allows them to avoid the interference of tissue autofluorescence.The repeatable excitation and in-situ free excitation feature enhance the application of them in bioimaging,sensing and nanomedicine.By integrating biosensing and bioimaging,the capability of near-infrared persistent luminescence nanoparticles to treat and image tumors can be enhanced.The biocompatibility and drug loading rate of nearinfrared persistent luminescence nanoparticles can be improved by surface modification.The functionalized composite probe has multiple imaging mechanisms,such as photothermal imaging,luminescence imaging and magnet resonance imaging.It can also be used in various therapeutic approaches such as photothermal therapy,photodynamic therapy and photoacoustic therapy.Due to the unique luminescent properties of persistent luminescence nanoparticles,nanoprobe that has dual imaging mechanisms of luminescence and photothermal imaging and multiple therapeutic modalities of photothermal therapy,photodynamic therapy and chemotherapy has been synthesized.The main contents are as follows.The Cr-doped zinc gallium indiumate persistent luminescence nanoparticles ZnGa_1.99-XIn _X:Cr³⁺（x=0,0.05,0.1,0.15,0.2,0.3,0.4）were synthesized by a hydrothermal method.The effect of pH on the luminescence properties of PLNPs was also investigated.The pH（pH=7,8,9,10,11）levels were adjusted by varying the amount of ammonia added during preparation,and ZnGa_1.89In_0.1:Cr³⁺was obtained under different pH levels.Finally,ZnGa_1.89In_0.1:Cr³⁺was obtained at pH 10.The crystal structure of this sample remained unchanged compared to ZnGa_1.99O₄:Cr³⁺,with a powder particle size at 15.36 nm and an afterglow lasting 96 hours.ZnGa_1.89In_0.1:Cr³⁺with In ion doping shows a significant increase in luminescence intensity and afterglow time compared to ZnGa_1.99O₄:Cr³⁺without In ion doping.Based on the excellent luminescent properties of ZnGa_1.89In_0.1:Cr³⁺,it can be used for the detection of dopamine through a photoinduced electron transfer mechanism（PET）.The changes in the luminescence intensity of PLNPs were investigated for dopamine concentrations in the range of 0.005-20μM.The luminescence signal diminished with increasing dopamine concentration and showed a good linear relationship with a correlation coefficient R²=0.9974 and a detection limit of 0.0024μM.The ZnGa_1.89In_0.1:Cr³⁺can be used as a nanoprobe with broad applications in the field of biosensing.The surface modification of the ZnGa_1.89In_0.1:Cr³⁺（ZGI）material was carried out.The ZGI was aminated by 3-aminopropyltriethoxysilane（APTES）reagent.The obtained aminated ZGI-NH₂was acylated with chlorin e6 to obtain ZGI-Ce6（ZGI-C）,and then MnO₂was characterized onto the ZGI-C by electrostatic interaction to obtain ZGI-Ce6@MnO₂（ZGI-CM）material.Finally,dopamine was polymerized on the ZGI-CM surface to form polydopamine（PDA）to get the ZGI-Ce6@MnO₂@PDA（ZGI-CMP）nanoprobe.A range of intermediates and ZGI-CMPs were analyzed using various characterization methods,which showed that Ce6,MnO₂and PDA were all successfully characterized.The Ce6 content in ZGI-C was calculated to be 26.94%,and the valence of the Mn element in ZGI-CM was determined to be positive 4 valence.In addition,a study of the photodynamic properties,photothermal properties and the ability of the nanoprobe to load and release drugs was carried out.The results showed that the sample could produce singlet oxygen and the presence of MnO₂enhanced the photodynamic effect,which confirmed that the composite probe ZGI-CMP had a dual response of pH/H₂O₂and GSH.The sample also had good photothermal stability with a photothermal conversion efficiency of 56.50%.The ZGI-CMP-DOX sample loaded with doxorubicin（DOX）was shown to have a drug loading of 5.33%and a drug loading efficiency of 29.6%.DOX release from samples in phosphate buffered solution（PBS）increased progressively with decreasing solution pH,which indicated that pH stimulated the response of samples to release DOX.A ZGI-CMP nanoprobe with multimodal imaging and multiple therapeutic modalities was prepared,which has potential applications in the fields of bioimaging and drug delivery.