Title: Biological synthesis and characterization of silver nanoparticles by the plant extract of gorakhmundi (Sphaeranthus Indicus)
Synthesis The synthesis of silver nanoparticles (AgNPs) via biological method has gained much importance and interest in the world of nanotechnology as it has many advantages comparing to traditional methods of synthesis including cost-effectiveness of method and use of non-hazardous reducing and stabilizing agents during the synthesis. The In this research, the synthesis was started by reaction of 1mM AgNO3 and different concentrations of plant extract of gorakhmundi of Sphaeranthus indicus starting from 1mL up to 10 mL separately. An important and beautiful aspect of the synthesis is the absence of any chemical catalyst, surfactant or template. Silver nanoparticles were synthesized successfully when silver ions (present in AgNO3 solution) reduced to silver nanoparticles upon treating with plant extract. AgNPs were then characterized and tested to observe their antimicrobial activity. Different analytical techniques such as, scanning electron microscopy (SEM), UV-visible spectrophotometer and Fourier transform infrared spectrometer (FTIR) were used to characterize the AgNPs. UV-Vis spectrophotometry monitored the stability and bio reduction of nanoparticles whereas SEM analysis were carried out to determine the surface morphology and particle size of AgNPs. FT-IR analysis explained nature of capping and reducing agents present in plant extract. Biological activity of AgNPs was carried out against different bacterial (gram negative and positive) strains including E. coli and B. subtilus and positive action against these bacterial strains was reported. In conclusion, the AgNPs were synthesized successfully using biological route which has ecofriendly effects and possess numerous medical and health benefits when compared to conventional methods.
Key words: biological synthesis, nanoparticles, silver nanoparticles, AgNPs, nanotechnology, antimicrobial activity, Fourier transform infrared spectrometer, scanning electron microscopy