Synthesis and Characterization of D-/L-methionine Grafted PEDOTs for Selective Recognition of 3,4-Dihydroxyphenylalanine Enantiomers

Two pairs of amino-acid functionalized poly（3,4-ethylenedioxythiophene）（PEDOT） derivatives, namely, poly（N-（tert-butoxycarbonyl）-L-methionyl（3,4-ethylenedioxythiophene-2＇-yl）methylamide）（L-PEDOT-Boc-Met） and poly（N-（tertbutoxycarbonyl）-D-methionyl（3,4-ethylenedioxythiophene-2＇-yl）methylamide）（D-PEDOT-Boc-Met）; poly（L-methionyl（3,4-ethylenedioxythiophene-2＇-yl）methylamide）（L-PEDOT-Met） and poly（D-methionyl（3,4-ethylenedioxythiophene-2＇-yl）methylamide）（D-PEDOT-Met） were synthesized via chemical oxidative polymerization of corresponding monomers. The structural characterization, spectroscopic properties and thermal stability of these monomers and polymers were systematically explored by FTIR spectra, Raman spectra, XRD spectra, UV-Vis spectra and thermogravimetric analysis. As chiral electrode materials, these polymers were employed to successfully recognize 3,4-dihydroxyphenylalanine（DOPA） enantiomers by cyclic voltammetry（CV） in sulphuric acid solution. The measurement results reveal that the tendency was hetero-chiral interaction between L-PEDOT-Met/PVA/GCE and D-DOPA, D-PEDOT-Met/PVA/GCE and L-DOPA, respectively. Also, the mechanism of chiral discrimination was discussed. All the results implied that the combination of electrochemical molecular recognition technology and chiral PEDOT materials can be a promising approach for chiral recognition and may open new opportunities for facile, biocompatible, sensitive and robust chiral assays in biochemical applications.

Electrosynthesis and Characterization of Aminomethyl Functionalized PEDOT with Electrochromic Property

We herein report the electrosynthesis of an aminomethyl functionalized poly（3,4-ethylenedioxythiophene）（PEDOT） derivative, poly（2＇-aminomethyl-3,4-ethylenedioxythiophene）（PEDOT-Me NH2）, in CH2Cl2-Bu4NPF6（0.1 mol·L^-1） system containing 2% boron trifluoride diethyl etherate（BFEE）. The electrochemical behavior, structure characterization, thermal properties and surface morphology of this novel polymer were systematically investigated by cyclic voltammetry（CV）, Fourier-transform infrared spectroscopy（FTIR）, thermogravimetry（TG） and scanning electron microscopy（SEM）, respectively. Electrochemistry results demonstrated that PEDOT-Me NH2 film displayed good redox properties and high electrochemical stability. Besides, PEDOT-Me NH2 films exhibited the electrochromic nature with obvious color changing from purple in the reduced form to blue upon oxidation. By further investigation, kinetic studies revealed that PEDOT-Me NH2 film had decent contrast ratio（41.8%）, favorable coloration efficiency（152.1 cm^2·C^-1）, low switching voltages and moderate response time（2.4 s）. Satisfactory results implied that the obtained PEDOT-Me NH2 film is a promising optoelectronic material and holds promise for electrochromic devices and display applications.