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Insight into the template effect of vesicles on the laccase-catalyzed oligomerization of N-phenyl-1,4-phenylenediamine from Raman spectroscopy and cyclic voltammetry measurements.

Authors :
Ležaić AJ
Luginbühl S
Bajuk-Bogdanović D
Pašti I
Kissner R
Rakvin B
Walde P
Ćirić-Marjanović G
Source :
Scientific reports [Sci Rep] 2016 Aug 26; Vol. 6, pp. 30724. Date of Electronic Publication: 2016 Aug 26.
Publication Year :
2016

Abstract

We report about the first Raman spectroscopy study of a vesicle-assisted enzyme-catalyzed oligomerization reaction. The aniline dimer N-phenyl-1,4-phenylenediamine (= p-aminodiphenylamine, PADPA) was oxidized and oligomerized with Trametes versicolor laccase and dissolved O2 in the presence of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) vesicles (80-100 nm diameter) as templates. The conversion of PADPA into oligomeric products, poly(PADPA), was monitored during the reaction by in situ Raman spectroscopy. The results obtained are compared with UV/vis/NIR and EPR measurements. All three complementary methods indicate that at least some of the poly(PADPA) products, formed in the presence of AOT vesicles, resemble the conductive emeraldine salt form of polyaniline (PANI-ES). The Raman measurements also show that structural units different from those of "ordinary" PANI-ES are present too. Without vesicles PANI-ES-like products are not obtained. For the first time, the as-prepared stable poly(PADPA)-AOT vesicle suspension was used directly to coat electrodes (without product isolation) for investigating redox activities of poly(PADPA) by cyclic voltammetry (CV). CV showed that poly(PADPA) produced with vesicles is redox active not only at pH 1.1-as expected for PANI-ES-but also at pH 6.0, unlike PANI-ES and poly(PADPA) synthesized without vesicles. This extended pH range of the redox activity of poly(PADPA) is important for applications.

Details

Language :
English
ISSN :
2045-2322
Volume :
6
Database :
MEDLINE
Journal :
Scientific reports
Publication Type :
Academic Journal
Accession number :
27561552
Full Text :
https://doi.org/10.1038/srep30724