Studies On Structural Designs Of Phosphonium-based Self-assemblies And Their Applications In Biosensors

As a new kind of self-assembly functional material,phosphonium ionic liquids have been widely used in organic chemistry,electrochemistry,functional material,biological medicine and so on.At present,there is no systematic research for theself-assembly structural design and the relationship between structure and properties of phosphonium.In this paper,new phosphonium compounds are synthesized through alkylation reaction,ester reduction reaction,acyl chlorination reaction,nucleophilic substitution reaction and anion exchange reaction based on ethyl protocatechuate,ethyl gallate,1,12-dibromododecane.Then,NMR was used to check their molecular formula,TG to analyze their thermal stabilities,POM to observe their phase state transitions and textures,DSC to determine their phase state transitions and XRD to characterize their structure arrangements.The study shows that the structure of phosphonium salt is correct and all of them have good thermal stability.The molecular structure has great effect on the thermal stability while the kinds of alkyl phosphine and anions have less effect on the thermal stability.The thermal stability of double phosphonium compounds is better than single phosphonium compounds.In addition,the melting point of phosphonium salt is related to the radius of its anion.The larger the radius,the lower the melting point.The melting point of triphenyl compounds is higher than tributyl and trioctylphosphine compounds.Some phosphonium salt shows texture of specific morphology in POM observation,and XRD confirms that phosphonium salt accords with layered structure.As a new analytical method,electrogenerated chemiluminescence biosensor has been widely applied in immunoassay,electrochemical reaction kinetics,biochemical reagents,food security and water quality tests.Meso-Tetra(4-carboxyphenyl)porphine(ZnTCPP)is a high intensive ECL Luminophores which can be stable in the aqueous phase.However,it often forms aggregation morphology on the surface of electrode and cannot exist as the active monomer which leads to the quenching fluorescence and UV and poor silence on the surface of electrode.In this paper,we use phosphonium salt as a carrier to load ZnTCPP,thereby constructing the phosphonium salt/ZnTCPP system.Then optimizing it through the molar ratio and modification,and choosing the optimum condition.By dint of that H2O2 can enhance the luminescence of the system,this system can achieve a biological technology for H2O2 detection in theory.