The Construction Of Switchable Pharmaceutical Electrocatalysis And Logic Gate System Of Flavonoids Based On Semi-interpenetrating Polymer Network And Nanomaterials

Objectives The electrocatalysis of nanomaterials and semi-interpenetrating polymer network（semi-IPN）hydrogel were applied to construct multiple switchable non-bioelectrocatalysis of flavonoids and molecular logic gate systems.In this dissertation,two types of multiple stimuli-reponsive semi-IPN hydrogel film electrodes including poly（acrylicacid）-poly（N-isopropylacrylamide）（PAA-PNIPAM）and poly（acrylicacid）-poly（N,N-diethyl acrylamide）（PAA-PDEA）were prepared.The drug molecules rutin and isoquercitrin as electroactive probes,the switchable properties of the film system were investigated.Using the electrocatalysis of nanomaterials,the new controllability drug electrochemical sensors were constructed Furtherly,a complicated drug molecular logic gate was constructed,which could lay the foundation for the development of drug molecular logic system.Methods（1）By drip coating,carboxylated multi-walled carbon nanotubes/N,N-dimethyl formamide（c-MWCNTs/DMF）suspension was dropped onto glassy carbon（GC）electrode surface.After drying,the GC/c-MWCNTs electrode was prepared.The PAA-PNIPAM semi-IPN pre-gel solution was synthesized with chemical polymerization method and c-MWCNTs/PAA-PNIPAM electrode was assembled by dropping pre-gel solution onto GC/c-MWCNTs electrode surface.Electrochemical impedance spectroscopy（EIS）and CV method were utilized to characterize the film electrode.Rutin used as electrochemical probe,the multiple switchable property of the film system was explored and the logic gate network was fabricated.（2）Using drip coating method,the PAA-PDEA semi-IPN hydrogel film was assembled on the GC electrode surface.The multiple switchable CV behaviors of rutin molecules on the GC/PAA-PDEA film electrode were studied.The logic gate and simple logic device were constructed.Then by square wave voltammetry（SWV）method,the rutin was determined quantitatively.（3）Using layer-by-layer（Lb L）assembly method,the electrostatic interaction between chitosan（CS）and gold nanoclusters supported on carbon nitride（AuNCs@N-C）was used to assemble{CS/AuNCs@N-C}₃ film onto the surface of pyrolytic graphite（PG）electrode.Then PAA-PNIPAM pre-gel solution was drip-coated on the surface of the Lb L film electrode to form{CS/AuNCs@N-C}₃-PAA-PNIPAM film electrode in nitrogen atmosphere.Drug molecule isoquercitrin molecules were used as electroactive probe to investigate the multiple switchable characteristics of film electrodes toward different external stimulus,and the logic gate network with multiple iniputs and outputs would be constructed based on the electrocatalysis of AuNCs@N-C.Results（1）In the pH 4.0 solution at 25℃,the CV reduction peak current(I_pc)of rutin for the c-MWCNTs/PAA-PNIPAM film electrode was the largest.When the film electrode was at high temperature of 41℃or 0.35 M Na₂SO₄ solutions,the I_pc of rutin was significantly reduced.Based on the electrocatalysis of c-MWCNTs,according to the size of-I_pc,a4-input/3-output logic gate was constructed.（2）When the GC/PAA-PDEA film electrode was in pH 8.0 buffer solution at 25°C,the rutin displayed a larger CV response signal.With the solution temperature rising to 41°C or 0.35 M Na₂SO₄ solution adding,the CV signal of the rutin as probe was significantly dropped or even disappeared.A 3-input/3-output logic gate system and 2-to-1 encoder were constructed based on the switchable-I_pc of rutin.（3）At 25°C,isoquercitrin molecule showed a larger CV response,after treating the{CS/AuNCs@N-C}₃-PAA-PNIPAM film electrode with pH 4.0 buffer solution.However,when the electrode was at the 41℃or the addition of 0.35 M Na₂SO₄ condition,the CV response of the probe was significantly reduced.The logic gate would be construted using the non-bioelectrocatalytic properties of AuNCs@N-C and the level of-I_pc.Conclusions（1）The c-MWCNTs/PAA-PNIPAM film electrode exhibited pH,temperature,and SO₄^2--concentration sensitive triple switchable characteristics for rutin molecules.The4-input/3-output logic gate was built successfully based on the electrocatalytic amplification of nanomaterial c-MWCNTs,increasing the types and quantities of input signals of the logic gates.（2）Rutin also showed the triple switchable CV behaviors for the PAA-PDEA film electrode.The logic gate with 3 inputs and 3 outputs and the 2-to-1 encoder were constructed.（3）The{CS/AuNCs@NC}₃-PAA-PNIPAM film electrode exhibited the multiple switchable characteristics for isoquercitrin molecules.The assembly of metal nanomaterial AuNCs@N-C could make the CV response signal amplified and the difference of the multiple switching states increasied.And the corresponding logic gate network would be constructed.