Preparation And Application Of Nanomaterials Based On Biological Mass Spectrometry Detection Technology

Nanomaterials have attracted great interest from researchers due to their large specific surface area,superior adsorption performance and high optoelectronic properties,and are widely used in photocatalysis,photoelectrochemical sensing,adsorption and purification,ceramics and biological applications.High-throughput mass spectrometry has been widely used in proteomics and detection of small organic molecules due to its simple,rapid and sensitive analytical characteristics.Organic small molecule compounds such as dyes,surfactants,and perfluorinated compounds can cause damage to ecosystems and harm the living environment and human health.Changes in post-translational modifications such as proteomics such as phosphorylation,glycosylation,and methylation have predictive and therapeutic effects on human disease and health.Therefore,research on efficient,high-throughput,rapid detection and analysis based on proteomics and environmental pollutants has both significant socio-economic significance and important basic research significance.Nanomaterials can be used as adsorbents to enrich low-abundance biomolecules due to their high specific surface area,and can be used for efficient laser desorption ionization of target analytes due to their good light absorption capacity and fast energy transfer efficiency.Based on this,this thesis developed titanium-based and carbon-based nanomaterials,combined with its unique structure and properties,for high-throughput mass spectrometry to quickly and sensitively detect biomolecules such as small molecule pollutants and phosphorylated proteins in complex samples.Therefore,the main research contents and results of this paper are as follows:?1?Cobalt doped nanoporous carbons?Co-NPCs?with dodecahedral shape were pyrolytically synthesized and applied as a sorbent and matrix for the enrichment and analysis of small molecules by surface-assisted laser desorption/ionization time-of-flight mass spectrometry?SALDI-TOF MS?.Extremely low detection limits were accomplished for cetyltrimethylammonium bromide?1 fg/mL?,and rhodamine B?1 fg/mL?in water,and Malachite Green and its metabolite in fish blood and fish extracts at pg/mL concentrations.?2?Phosphorylated proteins exhibit extremely low abundance due to the presence of high levels of non-phosphorylated polypeptides and therefore require enrichment prior to matrix-assisted laser desorption ionization time-of-flight mass spectrometry?MALDI-TOF MS?analysis.To the best of our knowledge,TiO₂ materials have been extensively enriched for phosphorylated polypeptides.Based on this,a novel Bi_0.15Fe_0.15TiO₂ nanocomposites(Bi_0.15Fe_0.15TNs)were synthesized for the first time by a modified sol-gel technology,and successfully applied to selective extraction and enrichment of phosphopeptides from digested protein mixture solutions and real samples?tissue protein extract from human liver?.The co-doping of Bi and Fe into TiO₂ results in a significant enhancement in both the enrichment efficiency and selectivity.Compared with the commercial TiO₂ extractant,the proposed Bi_0.15Fe_0.15TNs possess a lower detection limit(2 x 10^-9 M)and higher selectivity at a low weight ratio of phosphopeptides/nonphosphopeptides?1:1200?.Additionally,a total of 223 phosphorylation sites were identified from the human liver lysate after enrichment by the Bi_0.15Fe_0.15TNs.Besides,the synthesis of Bi_0.15Fe_0.15TNs is quite easy,of high yield and inexpensive.?3?Increasing the visible light absorption of TiO₂ materials and improving its photocatalytic performance is still a hot research topic.In this section,two-dimensional reduced titania nanosheets?BTTNs?,synthesized by a solvothermal method,reveal significant visible light-activated germicidal activity.XRD,XPS,EPR,TEM and Raman show successful reduction of anatase TiO₂,resulting in Ti³⁺formation as well as an increase in the concentration of{001}facets.The BTTNs possess a bandgap energy of approximately 2.86 eV,and demonstrate strong absorption over the visible spectrum.Under simulated sunlight,RhB and E.coli were completely degraded and successfully monitored by matrix-assisted laser desorption ionization time-of-flight mass spectrometry?MALDI-TOF MS?.Our research shows that BTTNs have important application potential in wastewater treatment and clinical environment under ambient light conditions.