Research On Construction And Performance Of Bimetal MOF-based Biosensor

Metal-organic frameworks?MOFs?,constructed by coordination bonds between metal ions and organic ligands,are promising materials because of their porous crystalline structures,abundant compositions,and easy preparation.MOFs exhibit interesting properties and significant applications in a variety of fields,such as gas storage or separation,catalysis,energy conversion,sensors,and biomedical diagnosis.First,we prepared a bimetallic CeFe-based metal organic framework?CeFe-MOF?as a precursor,and calcined at high temperature to produce a nanostructure of porous carbon embedded with bimetallic cerium and iron oxide?by CeO₂/FeO_x@mC?)to detect carbohydrate antigen 19-9?CA19-9?.The results show that the CeO₂/FeO_x@mC₅₀₀ complex formed by calcination at 500?shows high mutual binding between the antibody molecule and the complex matrix,and has a high detection sensitivity for CA19-9.The sensor has a low linear detection range of 0.0001 to10 U·mL^-1 and a detection limit as low as 0.000025 U·mL-1?S/N=3?,and excellent selectivity,good stability,repeatability and practicability.Secondly,we designed and synthesized two new core-shell bimetallic Tb-MOF-on-Fe-MOF and Fe-MOF-on-Tb-MOF nanostructures using the MOF-on-MOF method and used them as aptamer sensors to transducer material anchors CA125 aptamer and detect CA125.The electrochemical results show that the Tb-MOF-on-Fe-MOF provides an extremely low detection limit of 58?U·mL^-1 towards CA125,and has has high selectivity,good stability,acceptable reproducibility,and excellent applicability in human serum.Moreover,the Tb-MOF-on-Fe-MOF nanoarchitecture demonstrates superior biocompatibility and good endocytosis,and could be directly used to detect live cancer cells,human breast cancer cells?MCF-7?.Finally,we synthesized a novel Co-based metal-organic framework?Co-MOF?and a nanostructure of terephthalonitrile-based covalent organic framework?TPN-COF??represented by Co-MOF@TPN-COF?It was constructed as a biological platform for unlabeled aptamer sensors to detect the most commonly used?-lactam antibiotic ampicillin?AMP?.When AMP was detected by electrochemical impedance spectroscopy,the manufactured aptamer sensor based on Co-MOF@TPN-COF showed 0.217 fg·mL^-1 at an AMP concentration of 1.0 pg·mL-1 to 2.0 ng·mL^-1 ultralow detection limit of.In addition,the aptamer sensor also shows high selectivity,good reproducibility and stability,acceptable reproducibility,and good applicability in human serum,river water and milk.This paper proposes new ideas for preparing MOFs-based composite materials and constructing electrochemical aptamer sensors,which may be used to detect other important biomarkers and have potential application value in the field of early diagnosis.