Synthesis and Optimization of Silver Nanoparticles using Leaf extract of Tamarindus indica by Box-Behnken Design for Enhanced Antimicrobial Activity

In the present study, eco-friendly synthesis of silver nanoparticles using aqueous leaf extract of Tamarindus indica as a reducing agent were carried out to in order to enhance antimicrobial activity of extract. In addition, different factors involved in silver nanoparticle synthesis was optimized by response surface methodology via Box-Benkhen Design (BBD). Silver nanoparticle synthesis was carried out by using aqueous leaf extract of Tamarindus indica by biological reduction method. The optimisation of different factors involved in synthesis were done by response surface methodology via Box-Benkhen Design (BBD). Using BBD, investigation of effect of different factors (independent variables) such as volume of Tamarindus indica extract, temperature and concentration of silver nitrate on particle size and polydispersiblity index (responses) of silver nanoparticles were carried out. Quadratic polynomial model was used for mathematic modelling and response surface analysis were performed for understanding the factor-response relationship. Further the optimized silver nanoparticles were characterized by UV-Visible spectroscopy, FTIR spectroscopy, Scanning electron microscopy and Transmission electron microscopy imaging studies. Optimised silver nanoparticle formulation was subjected to antibacterial activity studies against Escherichia coli and Staphylococcus aureus. Production of silver nanoparticles using 5ml of aqueous leaves extract of Tamarindus indica, 0.055M silver nitrate concentration at a temperature of 50°C was found to be the optimized condition. Optimised silver nanoparticle formulation showed SPR peak at 423nm and was spherical in shape with particle size of 148±0.11 nm and PDI of 0.2±0.09. Antibacterial activity study indicated that synthesized silver nanoparticles had better antimicrobial activity than aqueous leaf extract of Tamarindus indica. The antimicrobial activity of tamarind extract was improved by formulating into silver nanoparticle by eco-friendly approach and this study highlighted the different associated factors which influences the quality of silver nanoparticles and thereby achieving successful synthesis of silver nanoparticles with the improved antibacterial effect.