Dual activity of laccase-lysine hybrid organic–inorganic nanoflowers for dye decolourization

Abstract

Abstract The laccase-lysine hybrid nanoflower was prepared by mixing aqueous CuSO4 solution into phosphate buffer solution containing laccase and lysine in one pot. The prepared laccase-lysine hybrid nanoflowers exhibited dual catalytic activity, i.e. enhanced laccase activity and peroxidase like activity. The presence of lysine and copper ions induced favourable conformational changes in the laccase, which led to ∼ 270% enhancement in enzyme activity. The prepared laccase-lysine hybrid nanoflowers were confirmed and characterized by SEM, FT-IR, and PXRD. Further, hybrid nanoflowers showed 2.75 folds increase in half-life in the temperature range of 40–70 °C as compared to free form. In addition, hybrid nanoflowers exhibited a higher rate of reaction ( V max value) with respect to its native form. The remarkable reusability and storage stability were also achieved by hybrid nanoflowers by maintaining 61 and 90% of its original activity upon six successive cycles and after 24 days of storage, respectively. Finally, the hybrid nanoflower was employed for decolourization of Reactive Blue 4 dye in the presence of H 2 O2. It showed 89% dye degradation within 1 h (30% higher than free laccase) which was attributed by the dual activity of hybrid nanoflowers.