Synthesis of polyaniline derivatives via biocatalysis

Abstract

Three structurally different aniline monomers, which can not be polymerized by chemical methods, have been polymerized with horseradish peroxidase. Enzymatic synthesis of linear polyaniline requires template molecules to minimize branching in the polyaniline backbone. Monomers having methoxy and methyl blocking groups at the ortho or meta position could induce the conducting form of para-linked polyaniline without the use of an anionic template, such as SPS. A new mild peroxide, peroxyacetic acid, was identified and used to oxidize horseradish peroxidase in water.

Enzyme Initiated Radical Polymerizations

“…A rather unusual in situ generation of peroxo species was found accidentally by Samuelson and coworkers [27]. They found that a dioxane stabilizer (acetyl acetal) spontaneously hydrolyzed under the reaction conditions and was oxidized to peracetic acid, which then served as oxidant to initiate the polymerization of aniline (Figure 4).…”

“…In the absence of a suitable template aniline polymerizes with poor regioselectivity yielding complex, insoluble and non conducting polymers. However, e.g., in the presence of negatively charged PSS (and in the presence of protonated aniline, i.e., at suitable pHs) formation of the conducting emeraldine form is strongly favored (Figure 12) [27,[73][74][75][76][77][78][79].…”

“…For example Mita et al [60] showed that the phenylene content of poly(p-substituted phenols) increased with the hydrophobicity of the substituent. Blocking the o-position of aniline enabled selective polymerization of anilines yielding conductive emeraldines without the need for a template [27].…”

Synthesis and characterization of chemiluminescent conducting polyluminol via biocatalysis

“…In recent years, enzymes have been employed as biocatalysts to synthesize conducting polymers. [27][28][29][30][31][32] Peroxidases catalyze, obtained from natural and renewable sources have been found to catalyze the oxidation of a wide range of aromatic amines and phenols in the presence of hydrogen peroxide (H 2 O 2 ) to generate corresponding free radicals. These free radicals then undergo coupling to produce the dimmer, and successive oxidation and coupling reactions eventually result in the formation of the desired polymer.…”

Electrochemical Nanobiosensor for Glyphosate Herbicide and Its Metabolite

“…, suggesting that PSS played a role in doping the synthesized PDMA to the highly conducting emeraldine salt form [5].…”