Biofunctionalized silver and gold nanoparticles as potential curative agents

In this study, the bark of an important medicinal plant,Indigofera aspalathoidesis utilized as a bioreductant for the synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). The formation of nanoparticles was monitored, and the reaction parameters were optimized by UV-Vis spectroscopy. The attachment of biocomponents as stabilizer was proved employing Fourier-transform infrared (FT-IR) studies. Through transmission electron microscopy (TEM), the morphology was found to be predominantly spherical and a mixture of triangle and hexagon in the case of AgNPs and AuNPs, respectively. The crystallite size of AgNPs and AuNPs was affirmed through X-ray diffraction (XRD) studies using Sherrer formula as 22.03 and 47.70 nm, respectively. DPPH method was adopted to analyse the free-radical quenching ability, and the AgNPs, AuNPs and extract showed inhibition of 76%, 89% and 59% at a concentration of 200 mu g ml(-1), and the corresponding IC(50)values were 86.49, 55.20 and 149.19 mu g ml(-1). The binding of nanoparticles to calf-thymus DNA (CT-DNA) was through groove and the high binding constants (8.49 x 10(6)M(-1)and 2.34 x 10(7)M(-1)for AgNPs and AuNPs) point out the potential of these nanoparticles as curative drugs. The MTT assay showed that AgNPs were 100% toxic, and the low IC(50)value suggests that this can be used in the medicinal field as a safe drug.

Automated summary

In this study, bark of Indigofera aspalathoides was used as a bioreductant for the synthesis of silver and gold nanoparticles. The nanoparticles were characterized using various techniques, and their potential as curative drugs was indicated by their binding constants and toxicity levels.