Formulation and Evaluation of Silver Nanogel of Delonix elata & Its Antimicrobial Activity

Metallic nanoparticles (NPs) are a kind of nanomaterial with a size range of 1–100 nm and versatile forms based on variations in starting materials and synthetic methods. Delonix elata is a small sized tree found in Gujarat, western peninsular and southern India belonging to the family Fabaceae – Caesalpinioideae. The aim of study was the Formulation and evaluation of silver nanogel of Delonix elata & its antimicrobial activity. The seeds, leaves & bark of Delonix elata were collected from a local market in Lucknow, UP, India. The plant material, bark, leaves and seeds of Delonix elata were identified and authenticated by Dr. Sunita Garg, Scientist, Plant Diversity, Systematics and Herbarium Division, CSIR-NIScPR, New Delhi. Delonix elata seed, leaves and bark were extracted out using different solvents system i.e., ethanol, hexane and hydroalcoholic. Phytochemical screening was performed for all the extracts. Bacillus subtilis (MTCC 441), Escherichia coli (MTCC 1573), Pseudomonas aeruginosa (MTCC 424), were procured from the Institute of Microbial Technology (IMTECH), Chandigarh, India. Firstly, nanoparticles were synthesized and evaluated for UV-visible spectroscopy. The silver nanogel was formulated by dispersing a gel-forming agent. The nanogel was characterized for physical appearances, droplet size & polydispersity index (PDI) and SEM analysis. The antimicrobial activity of silver nanogels was determined by the zone of Inhibition using cup plate method. On observation the phytochemical i.e., saponins, tannins, flavonoids, phenols, were found in abundance in the hydroalcoholic leaves extract of Delonix elata. The diameter of zone of inhibition was observed highest as 10mm, 10mm and 13mm at 100µg/mL in silver nanogel of bark (hydroalcoholic extract). It can be concluded that silver nanogel namely Silver nanogel of Delonix elata leaves, bark (Hexane extract), Silver nanogel of Delonix elata seed, bark (Hydroalcoholic extract) showed good antimicrobial activity against all the utilized microbial strains.