Novel Electrochemiluminescence System Of Silver-based Metal Organic Coordination Polymer For Sensitive Detection Of Biomolecules

The electrochemiluminescence(ECL)is an excellent analytical method.Recently,many nanomaterials have been used in ECL fileds include carbon dots,quantum dots,carbon and nitrogen compounds,and metal-organic coordination polymers.The nanomaterials have many advantages such as stronger luminous intensity,better biocompatibility,tunable luminescence wavelength,and resistance to photobleaching.Nowadays,metal-organic coordination polymers,especially metal-organic gels(MOGs)and metal-organic frameworks(MOFs),exhibit the good properties in ECL systems and have become the research hotspot.Our research focuses on the application of silver metal-organic coordination polymers in the ECL field,such as silver metal-organic gel(AgMOG)and silver metal-organic framework(AgMOF),and discusses their luminescence mechanisms and uses them for the detection of biomolecules.The specific content includes the following three parts:1.Novel ECL system with AgMOG as the enhancer was applied to quantify cytochrome C(Cyt C).Silver ions and 2,6-bis(2-benzimidazolyl)pyridine(BBPY)was mixed at room temperature and standed for 30 minutes to obtain AgMOG.The AgMOG can greatly enhance the ECL intensity of S₂O₈^2--O₂ system.The possible mechanism was ascribed to that the AgMOG could accelerate the electro-catalytic reduction of S₂O₈^2-.Then,the system was successfully applied to quantify Cyt C.There is a good linear range from 2 to 10 n M(R²=0.9912)with a detection limit of 0.96 n M.2.A novel ultrasensitive ratiometric ECL biosensor with AgMOG as the ECL enhancer for detecting the atxA mRNA.The AgMOG,as ECL enhancer,could accelerate the electro-catalytic reduction of S₂O₈^2-to SO₄?^-,which reacted with dissolved oxygen,resulting in strong cathodic ECL.Luminol was encapsulated in liposome as an amplified signal labels and the luminol anion radical also reacted with dissolved oxygen to create the anodic ECL emission.We immobilized luminol-encapsulated liposomes on the surface of AgMOG through the hybridization of DNA and mRNA.This would provide a competitive mechanism involving dissolved oxygen between K₂S₂O₈ and luminol.Benefiting from the competitive mechanism and amplified signal ways,this ratiometric biosensor was successfully applied to quantify atxA mRNA and achieved a wide linear relationship range from 10 to 300 f M with a low detection limit of 8.13 f M.3.A novel AgMOF as emitter was used to construct the new ECL system for the detection of mi RNA-107.The 1,1,2,2-tetrakis(4-(4-pyridyl)phenyl)-ethylene(TPPE)and Ag⁺were mixed at room temperature and standed overnight to obtain the AgMOF.The TPPE showed excellent aggregation-induced ECL(AI-ECL)property,but its ECL emission would be severely attenuated.However,AgMOF could produce strong and stable cathode ECL emission.The possible reason is that the state of TPPE becomes more orderly and concentrated after the formation of AgMOF.We used AgMOF as the donor and BHQ2 as the acceptor to construct an ECL resonance energy transfer(ECL-RET)system.The system was used to quantify mi RNA-107 from 20 to 120 f M with a detection limit of 4.33 f M.In this study,silver metal-organic coordination polymer as the materials and ECL as the technical were used to reveal the ECL properties of AgMOG and AgMOF.Moreover,the materials were used to fabricate biosensors for detecting biomolecules.The application of silver metal-organic coordination polymers in the ECL field has greatly expanded its research fields,and also enriched the types of choices for new ECL materials.