Fabrication,Property And Cell Imaging Analysis Of Cyclodextrin-aided Fluorescent SiO₂ Nanoparticles

The exploration of fluorescent tools with distinguished optical properties and favorable biocompatibility is significant for bio-sensing and bio-imaging.We herein present a host-guest interactions aided strategy for fabricating fluorescent silica nanoparticles(FSNPs),which is enabled by cyclodextrin(CD)supermolecules.Furthermore,we have studied their optical properties and applications in cell imaging analysis and ratiometric biosensing of p H value at living cell level.This master‘s thesis has four chapters as the following:The first chapter is an introduction.The basic overview for FSNPs was described.Firstly,FSNPs possess a few superior properties/functions including enhanced fluorophore photostability,increased brightness due to multiple dye encapsulation,multicolor fluorescent coding,versatile surface modification/functionalization,good biocompatibility,stable physical and chemical properties and so on.Then,we described some common synthetic methods and applications in bioimaging and p H ratiometric biosensing at living cell level.Finally,the existing problems and our working goal were put forward,respectively.In the second chapter,we studied the fabrication and property of cyclodextrin-aided fluorescent silica nanoparticles.Compared with conventional FSNPs,the modified products(are named as fluorophore@CD@SNPs)possess several advantages.First,the incorporated fluorophores can thoroughly get rid of their intrinsic aggregation due to CD‘s inclusion effect,and the fluorescence intensity of the obtained fluorophore@CD@SNPs can enhance 48-67%.Then,the fluorophores can be well fixed by the host CD molecules.As a result,the leak rates of the incorporated fluorophores are only 15-17%,which is about 3 times lower than that of conventional ones(42-48%).In general,the as-prepared fluorophore@CD@SNPs possess prominent optical property and versatile fabrication.In third chapter,we studied the application of the as-prepared fluorophore@CD@SNPs in biological imaging and ratiometric p H sensing at living cell using(indicator-reference)integrative silica NPs.First,compared with the conventional FSNPs,the as-prepared RB/R-6G@?-CD@SNPs are brighter and more stable in cell imaging analysis.Notably,the as-prepared fluorophore@CD@SNPs show observable lower cytotoxicity as compared with their conventional counterparts,probably due to the substantially decreased leakage of the incorporated fluorophores.Then,the as-prepared FL/RB@CD@SNPs have a good effect on p H sensing in living cell.In general,the as-prepared fluorophore@CD@SNPs not only possess well-suited for cell imaging analysis but are competent for(indicator-reference)ratiometric sensing of p H value at living cell level using(indicator-reference)integrative silica NPs.The fourth chapter included work summary and prospects of this paper.We first summarized the lightspot of the article,and then the development direction of work is also prospected.