Study On Preparation And Application Of Porphyrin Based Hydrogels In Microfluidic Bioanalysis

Biosensor is a kind of analytical equipment used to detect biological processes and convert them into photoelectric signals.In recent years,the types and applications of electrochemiluminescence sensors have been greatly enriched.At present,the main research direction of ECL biosensor is not only to develop new detection functions and realize low-cost replacement of existing detection and analysis methods,but also to combine ECL characteristics with flexible materials to develop flexible ECL biosensors that are easy to use in ordinary experimental environment and daily life.Currently,the common methods to develop flexible ECL sensors are based on thin film deposition technology.But the sensors obtained by this method are simple planar structure,which cannot meet the requirements of more complex device design.In order to solve this problem,this paper aims to develop a new flexible ECL biosensor using another method and explore its formation process.In order to develop a new type of flexible ECL sensor,the supramolecular hydrogel(G₄hydrogel)with guanosine as the main component was combined with zinc protoporphyrin(Zn PPIX)to form G₄/Zn PPIX hydrogel material with ECL properties.The conductive polymer Polyaniline(PANI)was further synthesized on G₄/Zn PPIX hydrogel fiber to obtain G₄/Zn PPIX/PANI hydrogel.The experimental results show that G₄/Zn PPIX/PANI hydrogel has excellent ECL properties.Then,it was found that many kinds of amines,such as tripropylamine,triethylamine,cysteine and 2-(dibutylamino)ethanol,could quench the ECL strength of G₄/Zn PPIX/PANI hydrogel,and the quenching efficiency was linear with the logarithm of amine concentration,indicating that it has potential ability to detect amine metabolites in human body.Finally,the G₄/Zn TCPP/PANI hydrogel prepared from tetra-(4-carboxyphenyl)porphyrin zinc(Zn TCPP)verified the ECL imaging application of ECL conductive hydrogel in the field of microfluidic chip.The ?-?stacking of porphyrins and G₄ lamellar monomers during GPP hydrogel formation is a self-assembly process in which ordered structures are formed by specific internal local interactions.To further understand this process,?microfluidic channels are used to simulate the model system of interaction between zinc(p-sulfonic)phenylporphin(Zn TSPP)receptor and imidazole ligand under ideal solution conditions.A positive correlation between the migration rate of porphyrin receptor and ligand concentration was observed by microfluidic platform,and the receptor-ligand relationship was established to describe the molecular interaction process.On this basis,a computational program was established to simulate and predict the interaction between porphyrin receptor and imidazole ligand.The simulation results were consistent with the actual experimental data:the average F_P of the chemical trend force of porphyrin receptor in the ligand gradient tends to 0 when the ligand concentration c_L is far less than the dissociation constant K_D,which corresponds to an insignificant chemical trend.When c_L?K_D,F_P?k _BTln2;When c_L>>K_D,the receptor is surrounded by excess ligand and F_P tends to be stable.The perfect agreement between simulation results and experimental phenomena also proves the applicability and accuracy of the algorithm,which can be further applied to describe the interaction between components in solution systems with other known parameters.