Studies On The Constitution And Application Of Electrochemiluminescence Energy Transfer Systems Based On Mn²⁺ Doped Upconversion Nanoparticles

Electrochemiluminescence?ECL?,which is arises from the high-energy electron transfer reaction between electrogenerated species,has become a powerful tool in analytical and clinical applications owing to its virtues such as easy controllability,high sensitivity,low background and no need of expensive instruments.Upconversion nanoparticles?UCNPs?have been proposed as a promising new member of ECL emitters because of their attractive chemical and optical features,including low toxicity,considerable ECL intensity,and stable cathodic signals,ect.Herein,the NaYF₄:Yb,Er/Mn UCNPs in red region and the NaYF₄:Yb,Tm/Mn UCNPs in near infrared?NIR?region were synthesized.Coupled with ECL resonance energy transfer?ECL-RET?,a series of sensitive,specific,stable and practical assays were built for determination biological analysis.?1?By using facile solvothermal technology,NaYF₄:Yb,Er/Mn UCNPs were prepared.An ECL-RET system between NaYF₄:Yb,Er/Mn UCNPs as donor and gold nanorods?GNRs?as acceptor was built.Based on the ECL quenching of NaYF₄:Yb,Er/Mn UCNPs,a simple and sensitive method was developed for the determination of alpha fetal protein?AFP?.Under the optimal conditions,the linear range and the detection limit for AFP are7.50-938 pg/mL and 7.20 pg/mL,respectively.The method was applied successfully to the determination of AFP in human serum with satisfactory results.?2?The as-prepared NaYF₄:Yb,Tm/Mn UCNPs exhibited a emission in the NIR region and were modified with poly?acrylic acid?.Then the prostate antigen ?PSA? antibody1 was covalently coupled to the carboxyl-functionalized NaYF₄:Yb,Tm/Mn UCNPs,which acted as the energy donor,while PSA antibody 2 modified GNRs as energy acceptor.When PSA was added,the distance between the donor and the acceptor was decrease via the specific interaction between antibody and antigen,resulting in high quenching efficiency.The linear range of detecting PSA was from3.75-938 pg/mL,with a limit of detection as low as 3.16 pg/mL.?3?In the study,we successfully synthesized NaYF₄:Yb,Tm/Mn UCNPs.By employing it as donor and GNRs with maximum absorption wavelength at 798 nm as acceptor,an ECL-RET system was built.After modified with thrombin aptamers,the ECL-RET system was subsequently demonstrated for the determination of thrombin?TB?in aqueous solutions and blood samples.Under the optimal conditions,the linear range and the detection limit for TB are 25.7-3.75×10³pM and 24.0 pM,respectively.