Phytosynthesis and Characterisation of Silver Nanoparticles Synthesised from Flower Extract of Roheda (Tecomella undulata G. Don)

Abstract

Green synthesis of silver nanoparticles was carried out using Tecomella undulat flower extract with 0.1mM silver nitrate solution. Within a few minutes colour change and variation of pH value could be observed. Synthesised nanoparticles were characterised through UV-Vis spectra, particle size analysis, zeta potential measurement, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) analysis and Atomic force microscopy (AFM). The UV-Vis absorption spectrum shows an absorption band near 450 nm, which is characteristic absorption peak of silver nanoparticle. The particle size distribution result showed two peaks at 5.23 nm (20.3 per cent) and 77.82 nm (79.7 per cent). XRD characterisation showed that these are highly crystalline silver nanoparticles having average size 12.5 nm. FTIR spectrum was recorded to identify the biomolecules involved in the synthesis process, which showed absorption band stretches at 2939.52 cm-1, 2877.79 cm-1, 2362.80 cm-1, 1228.66 cm-1, 1157.29 cm-1, 1014.56 cm-1, 831.32 cm-1and 785.03 cm-1. SEM image showed that particles were spherical in nature. The presence of Ag was confirmed by major peak of Ag in EDX spectrum. 2D and 3D images of silver nanoparticles were obtained by AFM and biogenic nanoparticles were measured in the size range between 20 nm - 70 nm. Various types of spectroscopic and microscopic characterisation indicated that these are stable silver nanoparticles synthesised from flower extract of Tecomella undulata.