Oxireductases in the Enzymatic Synthesis of Water-Soluble Conducting Polymers - Enzymatic Polymerisation - page 12

Scheme 5 Above : Polymerization of EDOT catalyzed by SBP using terthiophene as a redox me-
diator. Below : Proposed mechanism for the reaction. (Reprinted with permission from Nagarajan
et al. [ 44 ]. c 2008, American Chemical Society)

a b

1% terthiophene

pH 3.5
pH 4.0
pH 5.5

0.75% terthiophene
0.5% terthiophene
0.025% terthiophene

pH 5.0

300 400 500 600 700
Wavelength (nm)

800 900 1000 1100

300 400 500 600 700 800

Fig. 8 ( a ) UV-Vis spectra for polymerization of EDOT at different terthiophene concentrations.
( b ) UV-Vis spectra for polymerization of EDOT at different pH values. (Reprinted with permission
from Nagarajan et al. [ 44 ]. c 2008, American Chemical Society)

polymerization can be carried out even at pH 4.0 to yield doped PEDOT/PSSNa
polymer, as seen by the absorption beyond 700 nm. The UV-Vis spectrum of the
doped PEDOT/PSSNa closely resembled (Fig. 8 ) the PEDOT/PSSNa obtained from
a commercial source (Aldrich).