Thermal-assisted synthesis of gold nanoparticles using aqueous extract of Helicteres isora L. fruit: Characterization and antioxidant activity

A quick and one-pot method for the green synthesis of gold nanoparticles (AuNPs) using small amounts of aqueous extract of Helicteres isora L. fruit has been developed. The results showed that by increasing the reaction temperature from ambient to 95 degrees C, the time required to synthesize AuNPs was reduced significantly. The SEM image clearly showed the formation of spherical AuNPs with narrow diameter distributions in the range of 6-25 nm. AuNPs exhibited excellent free radical scavenging activity (IC50 = 4.98 +/- 0.03 mu g mL(-1)) in a short time due to their large surface area.