Modification Of Zinc Galliate Spinel Persistent Luminescent Material And The Application In Fluorescent Sensor

Persistent luminescence materials refer to kinds of fluorescent material that can store photon energy in traps with excitation and generate photon emission after the excitation is removed,which have wide applications in safety signs,instrument display and anti-counterfeiting marking with the excellent afterglow characteristics.With the rise of nanomaterials in recent years,long afterglow materials have been applied to living imaging and biomarker tracking/detection.However,most fluorescent probes require real-time excitation and lead to strong background autofluorescence.Fortunately,this interference from autofluorescence could be solved by persistent luminescence materials with time resolved spectra technique and consequently high signal-to-noise ratio can be realized.In addition,the near infrared long afterglow material also has the advantage of deep tissue permeability,so it is the excellent candidate for new fluorescent probes.However,the luminescence properties of near-infrared long afterglow materials still far from practical application,and it is crucial to construct fluorescent probes to biomarkers detection.In this paper,two kinds of Zn Ga₂O₄:Cr³⁺host based long-afterglow materials were prepared by doping Sn and co-doping Ge,Yb and Er,respectively.Then,the morphology and fluorescence properties are characterized by different methods.Novel fluorescent probes were constructed to detect Fe³⁺,glucose oxidase and carcinoembryonic antigen?CEA?.The main contents are as follows:1.The near-infrared long afterglow materials Zn Ga₂O₄:Cr³⁺,Sn⁴⁺?ZGSC?were prepared with doping Sn⁴⁺cation by combining hydrothermal synthesis with high-temperature calcination,Their surface was coated with a silicon shell to improve its dispersibility in the water phase.The results of XRD and TEM showed that the prepared long afterglow material with good crystallinity and belonged to a cubic spinel structure.The average particle size of Zn Ga₂O₄:Cr³⁺,Sn⁴⁺after calcination is larger than that of hydrothermal treatment,which were less than 200 nm.An obvious silicon layer can be observed on the surface,and it can stably disperse in the aqueous phase for more than 1 h.ZnGa₂O₄:Cr³⁺,Sn⁴⁺@SiO₂?ZGSC@SiO₂?has goodfluorescence performance at 695 nm and excellent chemical stability in the water phase without obvious influence of p H,which had good selectivity for Fe³⁺.The intensity of the fluorescent probe was gradually quenched with the increase of the concentration of Fe³⁺ions within a linear concentration range from 50?mol/L to 800?mol/L.And the low detection limit was 2.5×10^-5mol/L.Finally,ZGSC@Si O₂was applied to the quantitative detection of Fe³⁺in iron supplement oral liquid successfully,which proved that its potential application in the quality control of iron supplement nourishment.2.Based on the above result that the fluorescence of ZGSC@Si O₂can be quenched by Fe³⁺,and H₂O₂can oxidize Fe²⁺to Fe³⁺effectively.Therefore,the nanofluorescent probe ZGSC@Si O₂/Fe²⁺was constructed to achieve the quantitative detection of H₂O₂.The fluorescence intensity of the fluorescent probe was gradually quenched with the increase of H₂O₂concentration.When the concentration of H₂O₂is between 8×10^-5mol/L and 8×10^-4mol/L,the intensity of the fluorescent probe had a good linear relationship with the H₂O₂concentration,and the low detection limit is1.85×10^-6mol/L.Furthermore,since H₂O₂can be produced by the reaction of?-D-glucose and?-D-glucose oxidase,the quantitative detection of?-D-glucose oxidase can be achieved by measuring the concentration of H₂O₂.Therefore,the nanofluorescent probe ZGSC@Si O₂/Fe²⁺/?-D-glucose was constructed to achieve the quantitative detection of?-D-glucose oxidase.The reaction time,the concentration of Fe²⁺and?-D-glucose were optimized.The results showed that the intensity of the fluorescent probe was gradually quenched with the increase of the concentration of?-D-glucose oxidase.There was a good linear relationship between the fluorescence intensity and the concentration of?-D-glucose oxidase within 7?19?g/m L,and the detection limit is 3.78?g/m L.The near-infrared nano fluorescent probe ZGSC@Si O₂/Fe²⁺/?-D-glucose provides a potential detection method for the detection of glucose oxidase in the fields of industry,food and medicine.3.A hydrothermal synthesis method followed with high-temperature calcination was used to prepare three cations of Ge⁴⁺,Yb³⁺,and Er³⁺co-doped near-infrared persistent luminescence nanoparticles?PLNPs?Zn Ga Ge O₄:Cr³⁺,Yb³⁺,Er³⁺.The morphology,structure and fluorescence performance were characterized by XRD,TEM,and fluorescence spectra.The surface functionalization of persistent luminescence nanoparticles was further coupled with BHQ modified aptamers to construct near-infrared nano fluorescent probes.According to the FRET mechanism,the fluorescence of persistent luminescence nanoparticles can be absorbed by Apt-BHQ causing fluorescence quenching.When CEA is presence in the fluorescent sensing probe solution,the aptamer are separated from the PLNPs with the specific recognition of CEA,and the fluorescence of persistent luminescence nanoparticles will be restored.Therefore,the near-infrared long afterglow fluorescent aptasensor PLNPs-DNA-Apt was constructed for the quantitative detection of CEA.The results of selectivity experiments showed that prostate specific antigen,alpha fetoprotein,trypsin andbovine serum albumin had no obvious influence on PLNPs-DNA-Apt,indicating good selectivity for CEA.Both photoluminescence and time-resolved detection were used to detect CEA due to the afterglow characteristics of long afterglow materials.The results showed that the intensity of the fluorescent probe increased with the increase of CEA concentration.And time-resolved technology was superior to photoluminescence,which effectively eliminated the interference caused by autofluorescence of pleural effusion and hence the detection accuracy was improved.The linear concentration range of CEA detected by the aptasensor was 5 pg/m L?10000 pg/m L,and the low detection limit was 0.0851 pg/m L by time-resolved technology.The aptasensor had been applied to the determination of CEA in pleural effusion successfully,which proved that it has a broad application prospect in the field of biological detection.