Preparation And Properties Of Polyacrylamide Modified Electrode Via Electrochemically Mediated Atom Transfer Radical Polymerization(eATRP)

Chemically modified electrode is a very popular research direction in the field of electrochemistry and electrochemical analysis.Polymer modified electrode is a kind of important chemically modified electrode,which is widely used in the fields of electrochemical sensors,drug analysis,environmental monitoring and so on.There are many methods for the preparation of polymers,and the atom transfer radical polymerization(ATRP)is an important method for the active/controlled polymerization.It has a broad application prospect in many fields,especially in the field of material preparation.In this paper,polyacrylamide was prepared on the surface of Au electrode via electrochemical mediated atom transfer radical polymerization(eATRP),the polymer modified electrodes and electrochemical sensors were constructed,and successfully applied to the detection of trace heavy metal lead ion and biological macromolecule hemoglobin.Specific contents are as follows:1.The initiator of hydroxy thiophenols bromide(4-HTP-Br)was firstly prepared.Then 4-HTP-Br and of 4-aminothiophenol(4-ATP)were mixed self-assembled on the surface of the Au electrode.Polyacrylamide was prepared on the surface of Au electrode modified with mixed SAM via electrochemical mediated atom transfer radical polymerization(eATRP).The electrode modified with PAM(PAM/Au)was carefully examined by cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS),polarization modulation infrared reflection-absorption spectroscopy(PM-IRRAS)and scanning electron microscope(SEM).Further,the PAM/Au electrode was successfully used for the determination of Pb2+ ion by differential pulse anodic stripping voltammetry(DPASV).Under the optimal conditions,the PAM/Au electrode showed a linear correlation for Pb concentrations in the range of 3.0×10-3 to 2.0×103 ?g/L.The limit of detection(S/N=3.3)was estimated to be 3.7×10 4 ?g/L.Finally,polymer brush electrodes were applied to analysis Pb ion in an effluent.2.4-HTP-Br and 4-HTP were firstly mixed self assembled on the surface of the Au electrode.Then molecularly imprinted polymers(MIP)were prepared on the surface of Au electrode by electrochemically mediated atom transfer radical polymerization(eATRP)with hemoglobin(Hb)both as catalyst and template molecule.The condition for eATRP such as the potential,time and Hb concentration were selected and determined.The electrode modified with MIP(MIP/Au)was carefully examined by CV,EIS and SEM.Finally,the MIP/Au electrode was used as a biosensor and successfully applied for the determination of Hb by differential pulse voltammetry(DPV)measurement.The results of experiments showed that the proposed biosensor displayed a broader linear range and a lower detection limit for Hb determination when it was compared to those Hb sensors based on MIP.The linear range was from 1.0×10-10 to 1.0×101 mg/L with a detection limit of 7.8×10-11 mg/L(S/N=3.3).