Metal Oxide Nanosheets For High-throughput Mass Spectrometry Detection Of Polyfluorinated Compounds And Exosomes

Two-dimensional(2D)nanosheet(NS)has been widely used in various fields such as adsorption and purification,photocatalysis,electrochemistry,microelectronics and ceramics,due to its special properties such as high specific offset,small scattering,good adsorption performance and excellent photoelectric performance.Surface-assisted laser desorption ionization time-of-flight mass spectrometry(SALDI-TOF MS)is a simple,fast and sensitive analytical detection technique that plays a very important role in proteomics,ecological health and food safety.Polyfluorinated compounds(PFCs)are widely used in the production of various consumer products due to their unique physical and chemical properties,but due to the bio accumulation and environmental durability of certain polyfluorinated compounds(such as perfluorosulfonate PFOS,etc.),pose a threat to human health and living environment.Therefore,it is very important to detect the polyfluoro compounds in the environment quickly,simply and sensitively to protect the ecological environment.Exosomes are small vesicles secreted by cells,which interact with important regulatory roles in various cell-cell interactions,and more and more studies have shown that exosomes can become potential markers of early diseases and cancer clinical diagnosis.However,exosomes exist in various body fluids,the separation and purification steps of exosomes are very important for the next analysis.In this paper,self-assembled titanium dioxide nanosheets(TiO₂ NS)were developed and prepared,combined with surface-assisted laser desorption ionization time-of-flight mass spectrometry,high-throughput detection of polyfluoro compounds in actual water samples was carried out;and samarium doped calcium zirconate nanosheets(CaZrO₃:Sm)were developed for rapid,simple and efficient enrichment and isolation of exosomes in human serum.The main contents are as follows:(1)Preparation of TiO₂ nanosheets by self-assembly and SALDI-TOF MS high-throughput detection of polyfluoro compounds in water sources.Two-dimensional titanium dioxide nanosheets(TiO₂ NS)were synthesized by one-step hydrothermal self-assembly,and the comparison with P25 TiO₂ and conventional organic matrix ?-cyano-4-hydroxycinnamic acid(HCCA)was studied.The experimental results show that the self-assembled TiO₂ nanosheets can be analyzed by PFCs SALDI-MS.The sensitivity of TiO₂ NS is higher than that of commercially available P25 TiO₂ and HCCA.It can be detected that as low as 0.05 pg/mL TiO₂ NS still shows good reproducibility,with an RSD of 7.29-7.7%.The high-throughput identification of trace PFCs in real water samples indicates that TiO₂ NS can be used for the detection of trace small molecular compounds in complex water samples by SALDI MS.Compared with traditional methods,this method is simple and fast,with high throughput and high stability.(2)Sm-CaZrO₃ nanosheets are used for enrichment and separation of human serum exosomes.Samarium-doped calcium zirconate nanosheets(CaZrO₃:Sm NS)were synthesized by hydrothermal method,and developed a new strategy for enrichment and separation of human serum exosomes by using CaZrO₃:Sm.The captured exosomes by CaZrO₃:Sm NS can be completely eluted for next step analysis.The enrichment performance was compared with TiO₂ and CaZrO₃ without Sm doped.CaZrO₃:Sm NS showed higher efficiency and specific selection of exosomes enriching from complex exo some-containing samples-human serum.The enrichment efficiency of CaZrO₃:Sm NS for two target proteins is 59.7%and 61.6%higher than that TiO₂ and CaZrO₃ respectively,11.9%and 24.6%higher than TiO₂ and CaZrO₃,and the non-specific adsorption is 207%and 57.8%lower than TiO₂ and CaZrO₃ respectively.The high enrichment efficiency and specificity of CaZrO₃:Sm benefit from the synergistic effect of zirconium(Zr)and doped samarium(Sm),which have a strong affinity and coordination for the phosphate group on the exosome lipid bilayer ability.CaZrO₃:Sm can be synthesized simply,low cost,stable performance and can be reused.It can be predicted that it can be used as a powerful tool in the field of enrichment and separation of exosomes,which will help the next step exosome analysis.