Near Infrared Persistent Luminescence Nanoparticles-based Nanoprobes And Their Bioassay Applications In Blood Sample

Near-infrared(NIR)persistent luminescence nanoparticles(PLNPs)can still keep their emission after stopping the excitation.Owing to this unique optical property,the tissue autofluorescence background interference,scattered-light and biological tissue photodamage generated from in-situ excitation can be well avoided.In addition,NIR-PLNPs features deep tissue penetration when the emission wavelength is within the biological tissue window(650-950nm).Thanks to above-mentioned merits,NIR-PLNPs have been adopted in many fields such as bioimaging,sensing and nanomedicine.Herein,we proposed two NIR persistent luminescence nanoprobes for biomolecules detection in blood samples with high sensitivity and selectivity.Detailed research works are listed as below.(1)PLNPs i.e.ZnGa²O⁴:Cr³⁺(ZGC)with NIR emission,property,uniform morphologies and narrow size distribution are prepared by a hydrothermal method.ZGC PLNPs has an advantage in the excellent NIR persistence luminescence emission performance and optical stability.It is found in the study that the persistence luminescence of ZGC PLNPs could be quenched specifically by Hemoglobin(Hb).Thus,the Nanoprobes which can specifically recognize NIR persistence luminescence are designed without ligand modification.The detection mechanism is based on the dynamic quenching caused by the collision between Hb and ZGC PLNPs.Under the optimum experimental condition,the Hb linear detection range of the probes is 1-50 nM,and the detection limit is 0.13 nM.Finally,the nanoprobes is successfully applied to detect the level of Hb in serum samples.(2)In order to extend the application of this NIR-PLNPs in bioassay,suitable modification of NIR-PLNPs is necessary.First,APETS is applied for the generation of amino group on ZGC PLNPs.Then,dopamine-isothiocyanate(Dopa-ITC)for the further functionalization on the surface of ZGC PLNPs to produce ZGC-Dopa nanoprobe.Due to the strong binding between Cu²⁺and the surface amino and phenolic hydroxyl groups of ZGC-Dopa probe,persistent luminescence ZGC-Dopa quenched obviously because of the efficient charge transfer induced by Cu²⁺.Subsequently,in virtue of the strong affinity between thiol and Cu²⁺,Cu²⁺in the ZGC-Dopa-Cu²⁺hybrid will be released due to the formation of Cu-S bond.And thus,persistent luminescence of the hybrid is restored in the presence of biothiols.Under the optimum experimental condition,the limit of detections(LODs)of this nanoprobe for GSH,Cys and Hcy are 3.7?M,1.65?M and 1.95?M,respectively.Finally,this nanoprobe was successfully applied for the direct detection of Cys in serum with the results approaching with that measured by the commercial Cys Kit..