Synthesis of Novel Chiral L-Phenylalanine Grafted PEDOT Derivatives with Electrochemical Chiral Sensor for 3,4-Dihydroxyphenylalanine Discrimination

摘要

Two amino-functionalized chiral poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives, poly(N- (tert-butoxycarbonyl)-L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide) (PEDOT-Boc- Phe) and poly(L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide) (PEDOT-Phe), weresynthesized electrochemically via potentiostatic polymerization of corresponding monomers N-(tert- butoxycarbonyl)-L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide (EDOT-Boc-Phe) andL-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide (EDOT-Phe). The electrochemicalbehavior, structural characterization, spectroscopic properties, and surface morphology of two chiralconducting polymer films were systematically explored. They displayed excellent reversible redoxactivities, and rough and compact surface. Importantly, PEDOT-Boc-Phe and PEDOT-Phe modifiedelectrodes were used to identify 3,4-dihydroxyphenylalanine (DOPA) enantiomers by square wavevoltammetry (SWV) in sulphuric acid solution. It is interesting that the SWV peak currents ofenantiomers were found to be quite different and hence the enantiomers could be successfullyrecognized but the enantioselectivity was not observed using the common method of cyclicvoltammetry (CV). Satisfactory results implied that the obtained polymer films could play crucial rolesin the development of practical value and analytical application prospects.