Rapid Detection Of Myoglobin And Procalcitonin In Vitro By Immunochromatography With Upconversion Nanoparticles

Since the upconversion luminescence phenomenon was discovered,it had attracted much attention of many scholars for its excellent optical properties and great application prospects.Upconversion luminescence was based on a two-photon or multiphoton process,successively absorbed two or more photons and reached the luminescence level through no radiative relaxation,and transitioned to the ground state then generate short-wavelength photons.The emission of short-wavelength light was emitted by long-wavelength light,which the energy of the emitted photon is higher than that of the excitation photon,which was an anti-Stokes light emission.Upconversion nanoparticals as a novel biofluorescent marker had special properties such as photochemical stability,narrow emission spectrum,low fluorescence background,and no photobleaching.In addition,the biggest advantage was that infrared light was used as the excitation light source,which had a strong tissue penetration ability and little tissue damage,which had great application prospects in biological quantitative detection and biological living body imaging detection.Upconversion nanoparticals mainly include matrix,sensitizer and activator.Fluoride NaYF₄ was considered as the matrix with the highest upconversion efficiency and Yb³⁺was selected as the sensitizer because of its simple energy level structure and large absorption cross section.The activators mainly included Er³⁺,Tm³⁺,HO³⁺,Pr³⁺,etc and each activator ion had its own unique luminescence characteristics.This thesis mainly included two parts that the first part was the rapid detection of myoglobin based on upconversion nanoparticles NaYF₄:Yb,Er@NaLuF₄ binding immunochromatography.NaYF₄:Yb,Er,NaYF₄:Yb,Er@NaYF₄ andNaYF₄:Yb,Er@NaLuF₄ were synthesized by thermal decomposition method.The luminescence intensity of NaYF₄:Yb,Er@NaLuF₄ and NaYF₄:Yb,Er@NaYF₄ was about 25 times higher than that of NaYF₄:Yb,Er.Finally,NaYF₄:Yb,Er@NaLuF₄ were coupled to myoglobin antibody for detection of clinical serum samples.A standard curve with a linear regression equation of y=0.00157x+0.0314?R²=0.98916?was established with a linear range of 0.5 ng/ml-400 ng/ml,the detection limit of blank,limit of detection,and limit of quantitation were 0.1ng/ml.0.5 ng/ml and 0.5 ng/ml respectively.Determination of serum myoglobin?Mb?could be used as the most sensitive indicator of early diagnosis of acute myocardial infarction?AMI?.AMI was basically excluded if Mb was negative.Mb could also be used for the diagnosis of reinfarction or infarct extension under a re-elevation of Mb with clinical manifestations.The second part was the rapid detection of procalcitonin based on upconversion nanoparticles NaYF₄:Yb,Tm@NaYF₄ binding immunochromatography.The thermal decomposition method was used to synthesize NaYF₄:Yb,Tm@NaYF₄ and NaYF₄:Yb,Tm with uniform morphology,hexagonal phase,and the core-shell structure of NaYF₄:Yb,Tm@NaYF₄ was 4 times the fluorescence intensity of the naked-core structure NaYF₄:Yb,Tm.Finally,the core-shell nanoparticles NaYF₄:Yb,Tm@NaYF₄ were coupled to the procalcitonin antibody for detection of clinical serum sample.A standard curve with a linear regression equation of y=?50.16053-0.04349?/[1+?x/187.45781?-0.98639]+0.04349?R²=0.99185?was established with a linear range of 0.05ng/ml-50ng/ml,the detection limit of blank,limit of detection,and limit of quantitation were 0.02 ng/ml,0.03 ng/ml,and 0.05 ng/ml,respectively.Procalcitonin?PCT?was a glycoprotein that was elevated in plasma when severe bacterial,fungal,parasite infections,sepsis and multiple organ failure,mainly reflected the systemic inflammatory response.