Silver nitrate (AgNO3) was of analytical grade (AR) and purchased from E. Merck (India).
In the typical synthesis of silver nanoparticles, 10 ml of the aqueous extract of Padina
tetrastromatica was added to 90 ml of 1 mM aqueous AgNO3 solution in 250 ml conical flask and
kept at room temperature for 72 h at 120 rpm. Suitable controls were maintained
throughout the experiments