The ABTS+ radical was prepared
placing 5 mL of distilled water, 3.3 mg of potassium persulfate
(Sigma–Aldrich, Steinheim, Germany), and 19.4 mg of the ABTS
(2, 2 Azino-bis (2-ethylbenzothiazoline-6-sulfonic acid) diammonium
salt) (Sigma–Aldrich, Steinheim, Germany) reagent in an
amber glass flask