CONICET | Buscador de Institutos y Recursos Humanos

A non-soluble polyampholyte bearing carboxylic and imidazole groups was synthesized in one step from methacrylic acid, 2-metylimidazole and ethyleneglycol diglycidyl ether to mimic the stimuli-responsive binding properties and catalytic activity of biomolecules. It was tested as sorbent for proteins using bovine serum albumin and soybean peroxidase. The adsorption properties of the polymer for bovine serum albumin were optimal, attributed to the combination of acid and basic groups in both macromolecules, with a maximum loading capacity of 0.7307 g g-1. Soybean peroxidase was extracted from the seed using an acetate buffer solution that contained Ca2+, and directly adsorbed on the polyampholyte surface. The adsorption equilibrium was well described by Langmuir model. Then the complex was exposed to vapours of glutaraldehide to avoid desorption of the protein. The activity of the immobilized peroxidase was tested for different concentrations of hydrogen peroxide using phenol as substrate. The complex was packed and used as a continuous-flow enzymatic reactor for amperometric detection of phenolic compounds. Epinephrine was quantified in synthetic samples using 30 mM hydrogen peroxide in the mobile phase and detecting the oxidized product at 0 V vs Ag/AgCl. Then a complex between Mn(II) and the polyampholyte was tested as a mimetic manganese peroxidase, designed to improve the chemical stability of natural enzymes. The adsorption of Mn(II) was studied by FTIR and the equilibrium amount of metal ion bound to the surface followed the Langmuir model. It was tested as catalyst for 2,4 dichlorophenol degradation with 10 mM hydrogen peroxide, finding an increase of 30% in the amount of oxidized phenol at 60 minutes of reaction when the complex was prepared from MnSO4 instead of MnCl2.