Eco-friendly biosynthesis and characterization of silver nanoparticles using Tinospora cordifolia (Thunb.) Miers and evaluate its antibacterial, antioxidant potential

The present study reports an eco-friendly, rapid and easy method for synthesis of silver nanoparticles (AgNPs) using Tinospora cordifolia as a reducing and capping agent. The different factor such as silver nitrate (AgNO3) concentration, fresh weight of T. cordifolia leaf, incubation time, and pH affecting silver reduction was investigated using Response surface methodology based Box–Behnken design (BBD). The optimum conditions were AgNO3 (1.25 mM), incubation time (15 h), Temperature (45 °C) and pH (4.5). T. cordifolia leaf extract can reduces silver ions into AgNPs within 30 min after heating the reaction mixture (60 °C) as indicated by the developed reddish brown color. The UV-Vis spectrum of AgNPs revealed a characteristic surface plasmon resonance (SPR) peak at 430 nm. AgNPs were characterized X-ray diffraction (XRD) revealed their crystalline nature and their average size of nanoparticles was 30 nm as determined by using Scherrer's equation. Fourier transform infrared (FTIR) spectroscopy affirmed the role of T. cordifolia leaf extract as a reducing and capping agent of silver ions. Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) showed spherical shaped and confirming presence of elemental silver. The synthesized AgNPs was found higher antioxidant activity than plant extract by dot plot assay. In addition, antibacterial activity against Staphylococcus sp. (NCBI-Accession: KC688883.1) and Klebsiella sp. (NCBI-Accession: KF649832.1), showed maximum zone of inhibition of 13 mm and 12.3 mm, respectively, at 10 μg/mL of AgNPs. From the results it is suggested that the synthesized AgNPs showed higher antioxidant and antibacterial activity than the plant extract, thus signification of the present study is the production of biomedical products.