The New Conductive Polymers Used In Biosensors

Electropolymerization was studied of Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with normal dopants as well as two important biomaterials, L-glutamic acid sodium (Glu-Na) and dopamine hydrochloride (DA). The electrochemical properties and stability of the resulted PEDOT chemically modified electrodes were investigated.PEDOT films were prepared by potentiostatic electropolymerization from 3,4-ethylenedioxythiophene aqueous solution, with toluene-4-sulfonic acid, p-toluene sulfonic acid sodium salt, 5-sulfosalicylic acid, sodium sulfosalicylate, lithium perchlorate, potassium bisulfate and sodium sulfate as the supporting electrolytes, respectively. The applied potential for electropolymerization was determined by using linear sweep voltammetry (LSV). Electrochemical behavior of PEDOT films was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It showed that the kind of dopants had a great influence on CV and EIS. In addition, the adhesion of PEDOT films to the gold electrode substrate was studied. It was found that the adhesion of PEDOT films largely depended on the dopants used in the electropolymerization. PEDOT/Glu and PEDOT/DA chemically modified electrodes were prepared by ion-exchange method. Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectrometry (FTIR) and CV were employed to demonstrate the incorporation of Glu and DA into the conducting PEDOT films. The electrochemical behavior of PEDOT/Glu and PEDOT/DA films and their stability in reduced glutathione (GSH) solution were investigated. The results showed that the PEDOT films had good stability.