Study On Construction Of Electrochemiluminescence Immunosensor Based On Metal Organic Gel

The principle of electrochemiluminescence is that by applying a certain voltage on the electrode surface,an electrochemical reaction occurs between the light-emitting material and the co-reagent.When the light-emitting material in the excited state transitions back to the ground state through the relaxation process,an electrochemiluminescence signal will be generated.Electroluminescence combines the advantages of electrochemistry and photochemistry,which makes the electrochemiluminescence immunosensor more sensitive,stable,and reliable,enabling more accurate trace detection of disease markers.Therefore,electrochemiluminescence has been a hot topic of concern and research for scholars in recent years.Based on the metal organic gel material,an electrochemiluminescence immunosensor was constructed for the detection of disease markers.Metal organic gel materials have the dual properties of metal organic framework and gel,and have the advantages of high load capacity,high stimulation response,easy synthesis,prominent porous structure and large specific surface area.In recent years,with the deepening of the research on electrochemiluminescence,metal organic gel as a new type of electrochemiluminescence material has attracted extensive attention.Metal organic gel materials have great potential as candidate materials for efficient electrochemiluminescence.These properties have solved the problems of unstable signals and low efficiency of many electrochemiluminescence immunosensors.As a result,the sensitivity of the electrochemiluminescence immunosensor has been greatly improved.This topic mainly includes the following three parts:（1）Based on the resonance energy transfer between the zirconium metal organic gel（Zr-MOGs）enhanced graphite carbon nitride（g-C₃N₄）and Cu₂S,a quenching electrochemiluminescence immunosensor was constructed for the detection of carcinoembryonic antigen.In this work,loading porous Zr-MOGs onto g-C₃N₄improves the problem of insufficient stability of the light-emitting signal of semiconductor light-emitting materials,making the ECL signal of g-C₃N₄stronger and more stable.The UV absorption spectrum of Cu₂S highly overlaps with the emission spectrum of the donor,ensuring the occurrence of electrochemical luminescence resonance energy transfer（ECL-RET）.In addition,the Cu₂S surface of the snowflake structure has many bumps that can load more antibodies,further improving the sensitivity of the immune sensor.The ECL immunosensor constructed based on this method exhibits excellent performance in the detection of CEA,with a linear detection range of 0.01 pg/m L～100 ng/m L and a detection limit of 4.90 fg/m L（S/N=3）.（2）Based on highly efficient aggregation induced electrochemiluminescence,Aluminum metal organic gel（Al（Ⅲ）-Cbatpy-MOGs）generate electrochemiluminescence signals for the detection of carcinoembryonic antigen.Using Al（Ⅲ）-Cbatpy-MOGs as energy donors,hydroxycobalt oxide loaded with gold nanoparticles（Co OOH@Au NPs）have been used as receptors to construct a quenched electrochemiluminescence immunosensor based on resonance energy transfer,achieving sensitive detection of carcinoembryonic antigen.Al（Ⅲ）-Cbatpy-MOGs overcome the problems of complex synthesis steps and poor film forming effect of AIECL emitters at present,and can be rapidly synthesized in about 15s using conventional solvents at room temperature.Not only is it low in biological toxicity and high in stability,but its fibrous network porous structure can load more antibodies and fully contact with co reactants.Combined with its aggregation induced luminescence characteristics,it can further improve the sensitivity and stability of ECL immunosensors.The ultraviolet absorption spectrum of Co OOH@Au NPs and the emission spectrum of Al（Ⅲ）-Cbatpy-MOGs overlap well,and the quenching type ECL immunosensor constructed based on this shows good sensitivity,reproducibility,and specificity for the detection of carcinoembryonic antigen.The linear detection range is 0.01 pg/m L～100 ng/m L,and the detection limit is 1.38fg/m L（S/N=3）.（3）Ruthenium metal organic gel enhanced luminol anodic electrochemiluminescence was used for the detection of carbohydrate antigen 15-3.Ruthenium metal organic gel（Ru-MOGs）were used as electrode substrate,and Luminol was loaded on cerium dioxide with hollow nanospheres（Ce O₂@Luminol）As a marker,a signal enhanced immunosensor was constructed to detect carbohydrate antigen 15-3.Ru-MOGs not only have a good porous structure with a three-dimensional fiber network that can connect more antibodies,but also have the activity of peroxidase,which can catalyze H₂O₂to produce more superoxide anion O₂^·-.Reversible Ce³⁺/Ce⁴⁺redox pairs can also significantly increase the electron transfer rate and promote the production of O₂^·-.The constructed ECL immunosensor achieves dual amplification of ECL signals in the Luminol-H₂O₂system.Under the optimal experimental conditions,the accurate and sensitive detection of carbohydrate antigen 15-3 was successfully achieved.The linear detection range is 0.001～100 U/m L,and the detection limit is 0.000300U/m L（S/N=3）.