Preparation Of Microporous Organic Polymer Coated Silica Core-shell Materials And Their Application In Fluorescence Detection And Separation Enrichment

Function driven innovative materials can improve the analytical performance of complex samples and have great application potential in analytical chemistry research.Innovation in material fields can realize the qualitative and quantitative analysis of complex systems.As a new type of material,core-shell material can realize a variety of functions and make up for the inherent defects of a single material.Therefore,the core-shell material plays an important role in many fields.Due to the advantages of simple preparation,high mechanical strength and easy modification,silicon-based materials can be considered as the matrix of core-shell materials.In this work,two kinds of core-shell organic-inorganic composites were designed and fabricated,as the following:Schiff-base condensation reaction was often adopted to prepare conjugated microporous polymers（CMPs）.However,due to the relatively unstable imine bond in the product,the application of CMPs in strong acidic or basic environments was limited.For this purpose,three kinds of cyclized CMPs（x-CMP x=m,p,bi）were successfully prepared by Schiff-base reaction followed by an acid-catalyzed in situ cyclization with 1,5,9-triamine-triphenylene（TATP）,andm-phthalaldehyde（m-PA）,p-phthalaldehyde（p-PA）or4,4’-biphenyldicarboxaldehyde（bi-PA）as precursors.Through a"one-pot"method,these CMPs were also coated onto silica nanospheres,assigned as x-CMP@Si O₂（x=m,p,bi）,exhibiting core-shell structure and excellent monodispersity.As fluorescent sensors,the fluorescence quantum yields of three cyclized x-CMP@Si O₂（x=m,p,bi）were 15.3%,14.4%and 11.2%,respectively,which selectively generated fluorescence quenching response to Fe³⁺and Cr³⁺in aqueous solution,realizing their qualitative and quantitative detection.It is expected this feasible method would facilitate CMPs to be widely explored in fluorescence detection and other research fields.In order to further improve the mechanical strength and hydrophilicity of the material,through a"one-pot"method,a layer of microporous organic polymer was coated onto the surface of monodisperse amino-functionalized silica microsphere via amino-aldehyde condensation reaction with core-shell structure.Based on these properties,microporous organic polymer-coated silica microspheres were employed as the stationary phase for capillary liquid chromatography and successfully offered baseline separation of polar small molecules,such as pyrogallol and phloroglucinol.Additionally,the material could also serve as the sorbent of hydrophilic interaction chromatography.A total of 470 unique N-glycopeptides and 342 N-glycosylation sites mapped to 112 N-glycosylated proteins were unambiguously identified from 2μL of human serum,exhibiting a promising prospect of application microporous organic polymer-coated silica microspheres in the proteomics research.