Green synthesis of silver nanoparticles using seed extract of Alpinia katsumadai, and their antioxidant, cytotoxicity, and antibacterial activities

The green synthesis of nanoparticles using plants and their extracts is considered as a representative approach in material syntheses for environmental benignity. Numerous metal nanoparticles with potential bioactivities have been prepared based on plant extracts. In this paper, we report an eco-friendly technique for the preparation of silver nanoparticles (AgNPs) using seed extract of Alpinia katsumadai, and the evaluation of their antioxidant, antibacterial, and cytotoxicity activities. UV-visible spectroscopy, FETEM, EDX, SAED, XRD, DLS and FT-IR analysis were used to characterize the morphology and crystalline phase of AgNPs. The FETEM and DLS analysis showed AgNPs were quasi-spherical in shape, with an average diameter of 12.6 nm for the size distribution. The SAED spectrum of the AgNPs indicated their crystalline nature, which was further confirmed by the XRD studies. The FT-IR spectra revealed that phytochemicals from Alpinia katsumadai seed extract act as a capping and reducing agent for AgNP formation. The AgNPs showed distinctive free radical scavenging, potent antibacterial activity against different types of bacteria, and cytotoxicity activities. The results confirmed that Alpinia katsumadai is a potential bio-resource/biomaterial for synthesizing AgNPs with applications in antibacterial and antioxidant agents.