Laccase from T. versicolor (specific activity ≥ 10 U mg−1)was provided
from Sigma-Aldrich Company (CAS Number 80498-15-3), stored at
−20 °C and used as-received. One unit of enzymeactivity (U) is defined
as the amount of enzyme that oxidizes 1 μ mol of ABTS to colored products
(420 nm, ε = 36,000 M−1 cm−1) per minute.