Covalent Immobilization of Phenylalanine Dehydrogenase on GlutaraldehydeModified Poly (3,4-ethylenedioxy) Thiophene: Poly(styrenesulfonate)/ Polyvinyl Alcohol Conducting Polymer Composite Films for El

A new strategy was developed to investigate conducting polymer poly(3,4-ethylenedioxy)thiophene:poly(styrenesulfonate) (pedot:pss) properties and potential forenzymatic electrochemical detection of l-phenylalanine. pedot:pss was blended withpolyvinyl alcohol (pva) and further treated with glutaraldehyde (ga) to produce newconducting polymer composite films of pedot:pss/pva-ga on indium(tin) oxide (ito)-coated glass slides. phenylalanine dehydrogenase (phedh) was covalently immobilized onthe glutaraldehyde modified conducting polymer composite films to producepedot:pss/pva-ga-phedh films. using this strategy, pedot:pss remained chemicallyunmodified and its electrical properties was maintained in a matrix containing glutaraldehydemodified polyvinyl alcohol. electrochemical behavior of the conducting polymer compositefilms, before and after enzyme immobilization, was investigated using apotentiostat/galvanostat. cyclic voltammograms showed an oxidation peak of about 0.63 vfor pedot:pss/pva-ga (pedot:pss to pva ratio=1/1) and about 0.73 v forpedot:pss/pva-ga-phedh in different concentrations of l-phenylalanine inglycine/kcl/koh buffer solution (100 mm, ph=10.4). the redox properties ofpedot:pss/pva-ga films which is attributed to oxidation of pedot seems to contributeto electron transfer to the electrode during enzymatic reaction. results showed that thesystem is suitable for determination of l-phe in human urine for people withphenylketonuria