The Preparation Of Novel Boronate-Affinity Adsorbent And Its Application In Biological Samples

Critical vital substances,cis-diol biomolecules(CDB),such as saccharides,glycoproteins,catecholamine and nucleosides,have very close relationship with biological phenomena,so they have received tremendous attention in the research of life science.However,the direct analysis of nucleosides from real samples is seriously hampered by their low content in real sample and serious matrix interference.Therefore,exploring a high efficient and convenient sample pretreatment method is quite critical.Boronate affinity materials have played an important role in separation and enrichment of CDB owing to their reversible and selective reaction with CDB.However,there are still some issues for boronate affinity materials to be solved,such as high cost of material,complicated preparation procedure,low reusability,limited grafting density and low binding capacity.To solve these issues,we have done the following works.We prepared boronate-functionalized magnetic attapulgite(ATTA-Fe3O4-NH2-DFFPBA).The combination of magnetic nanoparticles and attapulgite not only increased the surface area of the magnetic material,which provide abundant binding sites for further modification,but also endowed the attapulgite with good magnetism,which is easy to be isolated.The resultant material exhibited superior binding capacity(13.78 mg g-1)for adenosine and was able to capture CDB from the mixture of high concentration interferences.Finally,this boronate affinity material was used to preconcentrate nucleosides from human urine.Although the material had high specific surface area,the limited density of functional groups still limited its adsorption properties.To solve this problem,many catenulate functional groups were grafted on the surface of attapulgite via atom transfer radical polymerization(ATRP),and then,gold nanoparticles were introduced to increase the surface area of the material.Finally,owing to the interaction between gold nanoparticles and thiol,boronate-affinity adsorbents were prepared by employing 4-mercaptophenylboronic acid as the monomer.The adsorption capacity of the prepared adsorbent can be as high as 30.83 mg g-1,higher than that of most reported sorbents.In solid phase extraction,multi-step and time-consuming centrifugation processes are involved for preparation of powder material.In the third research,we fabricated magnetic polysulfone(mPSF)capsules containing mesoporous silica of type SBA-15 functionalized by boronic acid derivative(S-IPBA@mPSF).Micro-pores on the surface of the capsules reduced mass transfer resistance,which is conducive for the analytes to diffuse into the capsules and contact with SBA-15.Meanwhile,highly crosslinked polysulfone avoided leakage of powder materials,and the Fe3O4 in the capsules enabled them to be easily isolated.The prepared material exhibited good recyclability and can be used five times at least.During extraction,the added surfactant,hexadecyl trimethyl ammonium bromide(CTAB),can be adsorbed on the surface of adsorbent through hydrophobic interaction.This can provide good entrapment media to obviously enhance the enrichment ratio and sensitivity of this method.Nucleosides in cells were extracted with the developed material sucessfully.Furthermore,the filter paper was used as the matrix owing to its tunable shape and size.Firstly,a layer of nonporous SiO2 was deposited on the surface of the filter paper to enhance the mechanical strength.Then,a further deposition was operated to increase the specific surface area.At last,the phenylboronic acid was grafted to the filter paper through the reaction with amino silane.The prepared adsorbent was inexpensive,easyto-handle,it also exhibited good binding capacity and excellent selectivity.The above work accomplished some achievements in reducing cost and simplifying preparation,but in practical application,all the operations were carried out by manual operation.So in the fifth work,melamine foam was used as the matrix,then its surface was deposited by graphene oxide to increase the specific surface area and provide accessible functional groups for later modification.At last,the phenylboronic acid was grafted through amidation reaction.During extraction,the foam was packed to solid phase extraction column,then the enrichment and elution of the analytes were accomplished by injection pump.The semi-automatic process can reduce the manual operation.The foam can also be installed to pre-column to realized full-automatic analysis.