Construction,Performance Control And Application Of High Sensitivity Rare Earth Based Optical Nanoprobes

In recent years,cancer has been a major threat to human life and health.The mortality of cancer is high,so if we can detect cancer early,it will help to realize an early treatment of cancer and improve the survival probability of cancer patients.At present,optical imaging has shown higher imaging sensitivity than the computed tomography(CT)imaging and magnetic resonance imaging(MRI).Therefore,we have made great efforts on building highly efficient,highly sensitivity optical nanoprobes.Lanthanide-doped upconversion nanoparticles(UCNPs)have triggered considerable interests as biological imaging probes for their unique upconversion luminescence(UCL)properties of exhibiting high energy shorter wavelengths emission under continuous near-infrared(NIR)excitation.Compared with the conventional organic fluorophores and semiconducting quantum dots,UCNPs can significantly minimize autofluorescence of biosamples,decrease the photodamage,and possess large penetrating depth in biotissue through NIR excitation,making them highly suitable for bioimaging probes.As an optimal biological nanoprobe,bright UCL and small diameter are rigorously required for the nanocrystal.Therefore,it is important for us to synthesize small sized nanocrystals with intense UCL under the excitation of NIR.Based on the above point,this paper aims to construct the rare-earth based optical nanoprobe with high sensitivity,precise structure,and controllable performance for in vivo biologic imaging and small tumor diagnosis.The main contents of the paper and research results are as follow:1.Construction,performance control and optical properties of rare earth based small hexagon NaLnF4 nanoprobes based on NIR-I region(1)We have successfully synthesized the NaLnF4 UCNPs with obvious phase transformation and small sized hexagonal phase structure by a simple M2+(Mg2+,Co2+)doping high-temperature coprecipitation method.The results indicating that the crystal size and phase can be controlled by doping M2+.(2)We have further studied the optical properties of NaYF4 nanocrystals doped with different concentrations of Mg2+.The results reveal that the pure hexagonal NaYF4 nanocrystals exhibit higher up-conversion luminescence properties,which lays a foundation for the early tumor diagnosis.2.Rare earth based small hexagon NaLnF4 nanoprobes for biological application and in vivo tiny tumor detection.Prior to in vivo bioimaging applications,the hydrophobic NaYF4 UCNPs were first converted into hydrophilic ones by using HCl treating method.Then we performed the in vivo bioimaging,the results show that NaYF4 nanocrystalline is an ideal optical nanocrystalline probe,which is mainly excreted from the body by the way of hepatobiliary metabolism.In addition,we have successfully performed the high senstivity in vivo small tumor(-3 mm)detection by using the probe.The results show that our designed hexagonal NaLnF4 nanoprobes with high luminescence efficiency are of great significance for the early small tumor diagnosis and the improvement of survival rate of cancer patients.3.Second near-infrared emissive lanthanide complex in vivo optical bioimaging(1)We developed a new generation molecular NIR ?-emitting probe based on Nd-diethylene triamine pentacetate acid(DTPA)complex.The structure and optical properties of ND-DTPA were characterized by fourier near infrared(FIR)spectroscopy and absorption spectra.The results show that the synthesized Nd-TDPA molecular probe possesses excellent NIR-?emission and is an ideal NIR-?optical probe.(2)We have successfully performed the NIR-? optical imaging with the new advanced molecular optical probe to NIR-? optical imaging.The results show that Nd-TDPA molecules are mainly excreted from the body by kidney clearance,which greatly reduced the liver damage and retention time in vivo.The designed molecular Nd-DTPA probe with bright narrow band emission at 1330 nm is successfully used for highly sensitive in vivo NIR ?a bioimaging with rapid renal excretion and high biocompatibility and optical-guided tiny tumor(down to?3 mm)detection for the first time.Moreover,the Nd-DPTA complex also holds great promise as an X-ray contrast agent.