**4. Antioxidant Activity of AgNPs**

The antioxidant activity of synthesized AgNPs was evaluated by DPPH and TEAC radical scavenging assays. The beech bark AgNPs exhibited free-radical-scavenging activity using both assays as shown in Table 1. The activity against DPPH and ABTS confirmed the antioxidant potential of the beech bark AgNPs. Significantly higher TEAC values were noted for TS1–TS2 as compared to TS3–TS4. Many AgNPs solutions have been evaluated for their antioxidant capacities, commonly associated with the content of phenolic compounds from plant extracts [17,30,31]. Beech bark contains a range of biologically active components, such as tannins and polyphenols, indicating that the antioxidant activity of the AgNPs has been enhanced by these bio-components.


**Table 1.** Antioxidant activity of AgNPs.

TE—Trolox equivalents; TS1—beech bark extract, pH = 4, AgNO3; TS2—beech bark extract, pH = 9, AgNO3; TS3—beech bark extract, pH = 4, AgC2H3O2; TS4—beech bark extract, pH = 9, AgC2H3O2. ± Standard deviation.
