*2.3. Anti-Oxidant Activity of the ZnNMs*

The anti-oxidant potential of the ZnNMs was determined as the free radical scavenging potential through neutralization of the 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) radicals [31,32]. The aqueous suspensions of the ZnNMs were prepared by dispensing a known amount of the ZnNMs in a defined volume of HPLC-grade water. The prepared dispersions (1 mL) were bath sonicated, incubated under the same conditions with 3 mL methanolic solution of DPPH (0.1 mM) for half an hour. Variable color development in the incubated solutions indicating the radical scavenging rate was measured as absorbance at 517 nm. The percent inhibition was compared with the values obtained for the butylated hydroxytoluene (BHT) as standard.
