A Rapid and Efficient Biosynthesis of Metallic Nanoparticles Using Aqueous Extract of Chia (Salvia hispanica L.) Seeds

This study reports the rapid and simple methodology for the biosynthesis of silver nanoparticles (AgNPs) using the aqueous extracts of Chia (Salvia hispanica L.) seed (AECS). This aqueous extract acts as the reducing agent, and the reduction of silver nitrate (AgNO3) solution at room temperature resulted in the synthesis of the AgNPs. The active phytochemical present in the AECS served as a stabilizing agent and favored the transition of Ag+ into the elemental silver. The UV-Visible absorption spectra of the reduced silver nitrate (AgNO3) solution showed an absorption band centered around 450 nm which confirmed the presence of NPs in the solution. The X-ray diffraction (XRD) analysis revealed the successful AgNP biosynthesis, and scanning electron microscopy investigations depicted the cubic phase of the NPs having spherical morphology with the particle size in the range of 40-60 nm. The Fourier transform infrared (FTIR) spectra confirmed the presence of various organic groups viz -OH, C=O, C-N, and N-H in the AECS solution and referred that these organic groups actually participated in the reduction of AgNO3 ultimately resulting in the development of the metallic NPs. The biogenic AgNPs exhibited the characteristics of enhanced free radical scavenging, reduction potential, and catalytic and antibacterial activities against pathogenic bacterial strains. A detailed mechanism of catalytic activity is discussed in this report. Furthermore, the AgNPs showed excellent antibacterial activity even at lower concentration (10 mu g). Thus, we have developed a simple, rapid, one-step, and eco-friendly non-toxic method for the development of active AgNPs showing a higher antioxidant property, higher reduction potential, and enhanced catalytic and antibacterial activities.