Preparation of metal doped nanoparticles using flower extract of Piper betle and its anti-bacterial investigations

Preparation of Silver, Gold and Zinc oxide nanoparticles was carried out by biological reduction method using Piper betle flower (Pbf) extract which has been known for its phytochemical constituents such as carbohydrates, phenolic compounds, amino acids, proteins etc. The nano products capped with plant extract Pbf-AgNPs, Pbf-AuNPs and Pbf-ZnONPs have been characterised by UV–visible spectrophotometer (UV–vis), Fourier Transform Infrared (FT-IR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Transmission Electron Microscope (TEM) and X-ray Diffraction (XRD) studies. The spherical and circular morphology of the green synthesised nanoparticles confirmed and supported by SEM and TEM analysis. The crystalline in nature of Pbf-AgNPs, Pbf-AuNPs and Pbf-ZnONPs were examined by an X-ray diffraction study (XRD). Optical band values were derived for nano products using UV–vis data. The anti-bacterial activities were examined on Gram-positive and Gram-negative bacteria. Among the nano products the Pbf-ZnONPs has shown potential inhibition in the range of 15 mm to 21 mm in positive bacteria and 10 mm to 14 mm in negative bacteria upon increasing concentration. Next to this Pbf-AuNPs has also shown promising results in the range of 7 mm to 12 mm and 9 mm to 20 mm in positive and negative bacteria respectively. The potentiality of nano products can be arranged Pbf-ZnONPs > Pbf-AuNPs > Pbf-AgNPs in terms of inhibition zone against microorganisms. We the pioneer to report Piper betle flower as potential capping agent for the green synthesis of Pbf-AgNPs, Pbf-AuNPs and Pbf-ZnONPs.