Construction Of Electrochemical Sensor Based On Electrophilic Substitution Reaction Of Phenylboronic Acid

Phenylboronic acid and its derivatives can react with mercury ion and hydrogen peroxide to form aminobenzene mercuric chloride and aminophenol.Based on this specific electrophilic substitution reaction,mercury ion and hydrogen peroxide can be detected.In this paper,the polyaminophenylmercuric chloride modified electrode was prepared by the electrophilic substitution reaction of polyaminophenylboronic acid and mercuric chloride.The electrode can enrich the mercury ions in solution to the surface of the electrode,so as to achieve high sensitivity and selectivity for the detection of mercury ions.The polyaminophenylboronic acid/reduced graphene screen printed electrode was constructed by cyclic voltammetry.The disposable current type artesunate electrochemical sensor was prepared by the electrophilic substitution reaction of polyaminophenylboric acid and artesunate.The first chapter introduced the components and applications of electrochemical sensors,mercury ion electrochemical sensors,artesunate electrochemical sensors.The detection methods of mercury ions based on the electrophilic substitution reaction of boric acid derivatives and mercury ions and hydrogen peroxide substances,and the research of one-time electrochemical sensors.Finally,the research content of this paper was introduced.In the second chapter,the polyaminophenylboronic acid modified electrode was prepared by the electrophilic substitution reaction of mercuric chloride and polyaminophenylboronic acid modified electrode.In the reaction process,applying potential step on the electrode can effectively control the formation of poly(aminobenzene)mercuric chloride.When the potential changes from 0.8 V(vs.Ag/Ag Cl)to 0.45 V(vs.Ag/Ag Cl),the maximum amount of poly(aminophenylmercuric chloride)formed on the electrode surface.Cyclic voltammetry,X-ray photoelectron spectroscopy(XPS)and ultraviolet visible absorption spectroscopy(UV-Vis)were used to characterize the prepared poly(aminobenzene)mercuric chloride.The negative chloride on the surface of poly(aminobenzene)mercury chloride modified electrode had a very strong coordination ability with mercury ions,which can effectively enrich mercury ions in solution on the surface of the electrode,thus achieving a highly sensitive and selective electrochemical detection of mercury ions.The linear range of the electrochemical sensor for detection of mercury ions was 0.05～75.0μM(R~2=0.9975),and the detection limit is 16.7 n M(S/N=3).The electrochemical sensor can be used for the detection of mercury in tap water.In the third chapter,the electrochemical reduction of graphene oxide on the screen printed electrode was carried out,and then the polyaminophenylboronic acid/reduced graphene screen printed electrode(PABA/r GNO/SPCE)was prepared by electropolymerization.Polyaminophenol was synthesized by the specific electrophilic substitution reaction between polyaminophenylboronic acid and artesunate.The polyaminophenol was characterized by cyclic voltammetry and UV-vis spectroscopy.Differential pulse voltammetry(DPV)was used to detect the current response of poly(aminophenol),so as to realize the detection of artesunate.The linear range of the disposable electrochemical sensor for artesunate was 5.0～210.0μM(R~2=0.9981),and the detection limit was 1.67μM(S/N=3).