The Construction Of Pharmaceutical/bio-electrocatalytic Switch And Logic Gate System Of Matrine Alkaloids And Enzyme Based On Stimulus-responsive Film Electrodes

Objectives The catalytic functional material and multi-stimulus responsive film were constructed on the surface of glassy carbon?GC?electrode,the adjustable properties of the films were investigated using electroactive drug molecules as probes,and a multi-input/-output logic gate system was constructed by electrocatalytic amplification of currents.A binary films were assembled on the surface of pyrolytic graphite?PG?electrode to investigate the switching characteristics of the films,and a complex logic gate network and molecular logic devices were builted by amplifying peak current with bioelectrocatalysis.Methods?1?Carboxylated multi-walled carbon nanotubes?c-MWCNTs?were obtained by oxidation of multi-walled carbon nanotubes?MWCNTs?with mixed acids,it was dispersed in N,N-dimethyl formamide?DMF?and then dropped onto the surface of GC electrode,c-MWCNTs/PDEA film electrodes were formed by dropping polyacrylamide?N,N-diethyl acrylamide??PDEA?hydrogel films onto the surface after drying.The film were characterized by Scanning Electron Microscopy?SEM?and Fourier Transform-Infrared Spectroscopy?FTIR?.The switching properties of the film electrodes were investigated with matrine and sophordine as electrochemical probes and the logic gate system was constructed by electrocatalytic amplification of current.?2?The{CS/Con A}_n layer-by-layer?LbL?electrodes were obtained by LbL assembly of chitosan?CS?and concanavalin?Con A?onto PG electrode surface.Then,by chemical polymerization,PDEA-GOD-HRP?GOD=glucose oxidase,HRP=horseradish peroxidase?was dropped onto the surface of{CS/Con A}_n to obtain{CS/Con A}_n-PDEA-GOD-HRP film electrode with binary structure.It was characterized by SEM,FTIR,and electrochemical impedance spectroscopy?EIS?.Potassium ferricyanide(K₃?Fe?CN?₆?was used as electrochemical probe to study the switching properties of the film electrodes.Glucose was added to amplify the cyclic voltammetry?CV?response through bioelectrocatalysis,and a logic gate system and other molecular devices were constructed according to the peak current values.Results?1?When assembled film electrode were at 25°C in pH 9.0 solution?containing no Na₂SO₄ and methanol?,matrine and sophoradine showed a large CV responses respectively;When the film electrodes were treated by the temperature of 40°C or 0.35 M Na₂SO₄ or 20%methanol,their peak currents were obviously reduced or even disappeared.The threshold range is divided according to the peak current,a 6-input/5-output binary logic gate system is built,and a 2-to-1 encoder is constructed on the same experimental platform.?2?When the film electrodes were at pH 4.0 buffer solutions at 25°C,K₃(Fe?CN?₆ showed obvious CV responses;When the film electrodes were treated by 40°C or pH 9.0 buffer solutions or containing 25%methanol,the peak current markedly reduced or even disappear.After adding 15 mM glucose,the peak currents were significantly increased.According to the level of electrocatalytic oxidation peak current,a 4-input/5-output binary logic gate system is biult.Based on the same experimental platform,ternary INHIBIT logic gate,ternary AND logic gate and parity checker are also successfully constructed.Conclusion?1?The c-MWCNTs/PDEA binary structure film electrode exhibits multiple sensitive switching properties,and a 6-input/5-output logic gate system and a 2-to-1 encoder were constructed.Matrine and sophoridine are electroactive drug molecules that exhibit significant electrochemical oxidation peaks.In theory,if the drug molecule has a significant electrochemical redox peak,it can be used as a probe molecule to investigate the switching properties of the film.The peak current of the drug molecule increases after electrocatalysis,which can increase the number of logic gate inputs and can be used for the construction of molecular devices.?2?The{CS/Con A}_n-PDEA-GOD-HRP film electrode exhibits pH,temperature and methanol sensitive switching properties.After adding glucose,it amplifies the oxidation peak current,increases the complexity of the logic gate,and builds a variety of logic molecular devices.Electrochemical studies of oxidoreductases can provide a model for understanding electron transfer and biocatalysis in real life processes,which provide an important basis for the development of novel regulatable electrochemical biosensors,and establish a theoretical foundation for the development of multi-functional logic computing.