Preparations And Applications Of Immobilized Metal Affinity Adsorbents Based On Magnetic Graphene And Magnetic COFs

Sample preparation is an important and preliminary process for most chemical analysis methods.Due to the diversity of samples,selecting the suitable adsorbents is of great significance for its analysis.In the past ten years,with the rapid development of materials science,some new adsorbent materials have shown superiority in sample pretreatment.As a magnetic solid phase extraction adsorbent,magnetic nanocomposites have broad application prospects in sample separation.Not only can it achieve rapid separation,but also the surface of magnetic nanocomposites can be grafted with various functional groups,which is convenient for further modification.In this paper,two types of immobilized metal affinity?IMA?adsorbents were constructed using magnetic graphene and magnetic COFs as the matrix,and the adsorption performance of the adsorbents was studied.The main contents are as follows:1.Using magnetic graphene as a matrix,poly?hydroxyethyl methacrylate??PHEMA?was grafted from polydopamine-coated magnetic graphene oxide by surface-initiated atom transfer radical polymerization?SI-ATRP?as a molecular bottlebrush backbone.Then poly?glycidyl methacrylate??PGMA?was grafted from the PHEMA backbone via the second SI-ATRP to afford the bottlebrush polymer grafted magnetic graphene,after that iminodiacetic acid?IDA?was anchored on the nanocomposites to produce the IMA adsorbent after chelating copper ions.The adsorbent was characterized by transmission electron microscopy,thermogravimetric analysis,etc.,and its adsorption properties were evaluated by using His-rich proteins?bovine hemoglobin,BHb?and other proteins?lysozyme and cytochrome-C?.The results show that the prepared adsorbent has high adsorption capacity for His-rich proteins,and the maximum adsorption capacity to BHb is 378.6 mg g^-1.The adsorbent was employed to purify Hb from whole human blood,and the results from SDS-PAGE demonstrated the excellent performance of the adsorbent for the purification.This indicates that IMA adsorbent has potential application prospects in enriching and purifying His-rich proteins.2.Using magnetic COFs as a matrix,alendronate sodium?AS?was grafted onto the surface of the magnetic COFs by post-synthesis modification,and then titanium ions were chelated to obtain a magnetic COFs-immobilized metal affinity adsorbent.The prepared materials were characterized by infrared spectroscopy and X-ray powder diffraction.The adsorbent has a core-shell structure,a large specific surface area,a size exclusion effect,and a good magnetic response.And the adsorbent is applied to the selective enrichment of small molecular nucleotides.The results show that magnetic COFs-immobilized metal affinity adsorbent has excellent selectivity and adsorption capacity for nucleotides,high recovery rate,and good recyclability.