Synthesis Of Rare-earth Doped Upconversion Nanoparticles And Its Applications In The Field Of Visualized Biosensor

This paper mainly discusses the fabrication process of a simple visualized solid-phase biosensor based on luminescence resonance energy transfer(LRET)from upconversion nanoparticles(UCNPs)to gold nanoparticles(Au NPs),which is used to quantitatively detect the nucleic acid sequences of Human enterovirus 71(EV-71).The specific contents of this paper are as follows:Chapter 1:We briefly introduce LRET,upconversion luminescence mechanism,the research background,physicochemical properties,and applications in biosensors of UCNPs and Au NPs.Subsequently,the basis and innovation of this paper are put forward.Chapter 2:We have a brief introduction on the research background and content of this paper.Currently,most biosensors based on LRET are carried out in liquid phase,which has some limitations for point-of-care testing(POCT),such as easy aggregation of nanoparticles and inconvenient carrying.To solve the problems,we immobilized Au NPs on the surface of quartz glass plate with volume less than 0.025 m~3,which effectively avoided the aggregation of Au NPs and increased the portability of the solid-phase biosensor.Based on this,compared with the traditional liquid-phase detection,the Au NPs-DNA-UCNPs solid-phase sensing system proposed by us was more suitable for POCT.Furthermore,instead of the classical process of immobilization of UCNPs on the interface to induce luminescence gradually weaken,our detection was activated by immobilizing Au NPs on the interface through a more(naked eye)noticeable luminescence lightened phenomenon.Finally,the combination of a home-build luminescence image capture device and an open-source Image J software could further facilitate this visual and quantitative detection,laying a good foundation for the development of an efficient POCT detection platform.