| Recently,Up-conversion luminescence imaging has become a new generation optical imaging method because of Anti-stokes effect which is that after the absorption of continuous-wave low-energy photons leads to the emission of high-energy photons.Traditional luminescencenano-probes include organic molecules.quantum dots and fluorescent materials.However,the luminous efficiency of quantum dots is low;fluorescent materials suffer from photobleaching under long time irradiation of near-infrared(NIR)laser;Organic molecules are highly toxic,these inherent defect are bad for biological application.Different from the tradition Up-conversion luminescence materials,Upconversion nanocrystals are characterized by narrow emission bandwidths,bsence of photodamage to live organisms,very low autofluorescence background,high signal-to-noise ratio and detection sensitivity,and low toxicity.These features render them very suitable for bio-imaging in vitro and in vivo as luminescent labels.Therefore,development of upconversion nanomaterials with NIR-to-NIR emission is important.Meanwhile,photothermal therapy(PTT)has attracted considerable attention due to these advantages of rapid,efficient,minimally invasive compared with traditional therapy methods including Chemotherapy,radiation and surgery.More importantly,people usually focus on the excellent up-conversion performance,ignoring the unique down-conversion emitting ability,whih can improve the spatial/temporal resolution of the image and improve the penetration depth.Based on this,In this paper,we firstly synthesiz the NaYF4 rare earth fluoride,studied its unique transformation luminescence performance,and then applied-it to biological imaging,an one-step hydrothermal method is used to construct low toxicity,high photothermal efficiency and photothermal stable Cu2-xsnano-probe as a photothennal reagent for the tumor treatment,based onrare earth materials and copper sulfide nanomaterials,we build a therapeutic platform for integration of imaging and treatment.The main research contents are as following:(1)Yb3＋/Er3+ doped NaYbF4 upconversion nanoprobes were successfully synthesized via a hydrothermal route.The characterization including morphology and crystalline phase,optical properties,and biological toxicity are carried out systematically.These results show that as-prepared NaYF4:Yb,Er nanoprobes present strong green 520/545 nm and red 660 nm UC emission.Finally,it is applied to biooptical imaging.(2)Water soluble Cu2-xS nanoparticles were prepared by one step hydrothermal method,and the systematic study of the Cu2-xS water solution with the concentration of 808 nm at different heating performance of excitation source,excitation temperature curve and Cu2-xS aqueous solutions with different concentrations of light in the same 808 nm,the results showed that Cu2-xS nanoparticles present excellent photo-thermal performance,so the Cu2-xS nanoparticles are good photothermal agent.In addition,we also used the Cu2-xS nanoprobe as a photothermal agent to achieve tumor therapy under the excitation of the 808 nm excited light source.(3)Based on lanthanide rare earth materials and Cu2-xS Nanomaterials,we developed a new general in situ growth method to build multifunctional nanoprobes to integrate imaging and therapy.The crystalline phase and morphology of the material were characterized,the optical/thermal properties were tested and the toxicity test was carried out.The results show that the structure of the material is stable,which overcomes the defect that the traditional electrostatic attraction method brings the structore easy to fall off.In addition,it not only exhibits excellent optical performance but also excellent photothermal properties,so that imaging and therapy can be integrated,finally,we successfully detect the small tumor and non-invasive brain blood imaging. |
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