Catalytic, antibacterial and antibiofilm efficacy of biosynthesised silver nanoparticles using Prosopis juliflora leaf extract along with their wound healing potential

The present study focuses on the catalytic, antibacterial and antibiofilm efficacy of silver nanoparticles (AgNPs) in an easy, rapid and eco-friendly pathway. Herein, we have synthesised AgNPs using an aqueous extract of P. juliflora leaf. The bioactive compounds present in the extract are responsible for the reduction of Ag+ to Ag-0. The particle synthesis was first observed by visual color change and then characterized using UV-visible spectroscopy to confirm the formation of AgNPs. The synthesis conditions were then optimised using critical parameters such as reaction time, AgNO3 concentration, extract to AgNO3 ratio and temperature of the reaction. The hydrodynamic size of the AgNPs with Dynamic light scattering (DLS) was 55.24 nm, while, was in the range of 10-20 nm as determined through Transmission Electron Microscopy (TEM). Further, Fourier transform infrared spectroscopy (FTIR) studies were conducted to discern the functional groups or compounds responsible for the reduction of silver nitrate as well as the capping of silver nanoparticles. Later, X-ray diffraction (XRD) results showed crystalline nature of the biosynthesized AgNPs. To evaluate their antibacterial potential, AgNPs were assessed through disc-diffusion assay, which resulted in an appreciable dose-dependent activity. The antibacterial potential was investigated through disc-diffusion assay against E. coli and P. aeruginosa. The Congo red agar (CRA) plate assay successfully revealed the anti-biofilm activity against B. subtilis and P. aeruginosa. Further, the catalytic activity of synthesised AgNPs was assessed against azo dyes such a Methylene Blue (MB) and Congo Red (CR) that resulted in its effective degradation of toxic compounds in a short span of time. Further, AgNPs were assessed for their wound healing potential.