Coupled Enrichment And MALDI-TOF-MS Analysis Of Vicinal Diols Using As-Prepared Boron Nanosheets As Matrix

As a soft ionization technology developed in recent years,MALDI is often used to detect macromolecular compounds such as proteins,peptides,and polymers.After continuous research and development,it has been widely used in microbiology,food,medicine and other industries.The method has the advantages of high sensitivity,fast detection speed,convenient sample preparation,high salt tolerance,and low sample demand.In order to improve the detection range of this method,a new type of nano-matrix came into being.For example,graphene,carbon dots,porous silicon,metal nanoparticles,etc.Although these nanomaterials have good matrix properties and can avoid the interference caused by the traditional matrix itself,they have the disadvantages of complicated preparation,difficult batch synthesis,and cannot be used for enrichment and detection at the same time.Two-dimensional boron nanosheets(2DBS)have attracted extensive attention in recent years,mainly due to their unique physical and chemical properties.However,due to its complex synthesis method and high requirements for equipment,its applications are few and far between.This thesis uses a top-down synthesis method to synthesize boric acid-functionalized two-dimensional boron nanosheets.This method is convenient,has low requirements for equipment,is simple to prepare,easy to prepare in batches,and has high product purity.The experiment shows that:The synthesized 2DBS has obvious ultraviolet absorption near the wavelength of 325 nm,which provides the conditions for2DBS as a matrix;The structure of 2DBS is simple,and there are almost no background impurity peaks.In the positive ion mode,small molecular compounds such as sugars and amino acids are used for MALDI-TOF-MS analysis,and have high detection sensitivity;O-diol structure is difficult to ionize,but the presence of BO₃^3-can promote the ionization of o-diol structure;2DBS has a large specific surface area,which increases the specific enrichment ability of the material for o-diol compounds;Moreover,BO₃^3-functionalized 2DBS can specifically enrich the carbohydrate compounds with o-diol structure,which has a good enrichment effect and can achieve the purpose of enrichment and MALDI-TOF-MS detection at the same time.Provides a new direction for the application of 2DBS and the development of MALDI-TOF-MS.The entire contents of this article are as follows:Chapter 1:Introduction of the development and current situation of MALDI-TOF-MS,especially the application of MALDI mass spectrometer in recent years,and the related information of matrix.Highlights the physical and chemical properties of 2DBS and the development in recent years.Chapter 2:Synthesis of 2DBS with BO₃^3-on the surface by top-down synthesis method,and characterize it by TEM,XPS,UV-Vis,etc.Subsequently,the reaction results of 2DBS and the compound with o-diol structure were analyzed by FT-IR and UV-Vis.Finally,MALDI-TOF-MS analysis was performed,proving that 2DBS was used as an enrichment material and matrix to enrich o-diol structure while detecting small molecule compounds.Chapter 3:Experimenting with the characterization of 2DBS by TEM,XPS,UV-Vis,etc.,confirmed the successful synthesis of 2DBS,and 2DBS has obvious ultraviolet absorption at 325 nm,which laid the foundation for 2DBS as a new nano-matrix.By comparing the traditional matrix with the proven 2DBS,the results show that 2DBS has no background interference,and also proves that the structure of2DBS is simple.In this paper,the combination of 2DBS and o-diol compounds was characterized by FT-IR and UV-Vis.The experiment proves that the BO₃^3-on the surface of 2DBS is successfully combined with o-diol compounds.It was successfully applied to the enrichment of o-diol compounds under complex conditions and MALDI-TOF-MS analysis.In this paper,2DBS was successfully synthesized and used for the first time as a new nanometer matrix for the detection of small molecule compounds and the enrichment of o-diol structural compounds by MALDI-TOF-MS.It provides a new direction for 2DBS in the fields of medical detection,life science and environmental science.