Enhancing laccase-assisted polymerization reactions with perfluorinated compounds

Abstract

The catalysis of reactions by laccases are oxygen-dependent. Perfluorinated compounds (PFCs) are known to increase the solubility of oxygen when compared with water being applied in several fields as gas-dissolving agents. Herein, PFCs like Zonyl, perfluorohexane (C6F14), and perfluorodecalin(C10F18) were explored as promising agents to increase the rate of oxygen available on laccase-assisted oxidation of catechol. The oxidation of catechol was performed with and without aeration, using reactors with different agitation regimens (orbital shaker water bath and vertical rotating reactor). The enzymatic reactions and the level of oxygen were monitored by UV-Visible spectroscopy and oxygen quantification, respectively. The polymerization yield was estimated in terms of polymer weight gain after laccase-assisted oxidation and the products of reaction were analyzed by 1H-NMR,MALDI-TOF and particle size measurements. After laccase oxidation, the poly(catechol) was successfully synthesized with a polymerization degree (DP) of 7 and a mean size of 115nm, independently on the PFCs and aeration conditions. The findings showed that all PFCs examined, particularly perfluorodecalin, had the ability to dissolve oxygen, increasing its rate during oxidation reaction. The yield of poly(catechol) is 1.25 times higher using perfluorodecalin, under aeration, compared to the reaction carried out only with laccase. We provide the first evidence that PFCs significantly increase the oxidation of phenols by laccase.