2.5.2. ABTS∙+ free radicals scavenging assay

To evaluate the ABTS∙+ free radical scavenging ability of AB AgNPs, 7 mM of ABTS∙+ was dissolved in double distilled water to which 140 mM of potassium persulfate solution was added. The mixture was incubated in dark for 14 h and before the experiment they were diluted to give an absorbance of 0.700 ± 0.02 at 734 nm. Various concentrations (2, 4, 6, 8 and 10 μg/ mL) of AB AgNPs were mixed with the diluted ABTS∙+ solution and incubated for 10 min. The measurements were taken at 734 nm and Ascorbic acid was used as the control (Seeram et al., 2006). The free radical scavenging ability was calculated as follows:

% ABTS∙+ radicals scavenging = (Absorbance of Control–Absorbance of Sample) × 100

Absorbance of Control