Rapid colorimetric detection of Hg2+ ion by green silver nanoparticles synthesized using Dahlia pinnata leaf extract

In this study, we for the first time reported green synthesis of silver nanoparticles from silver nitrate solution using leaf extract of Dahlia pinnata. Green synthesis was chosen over conventional physical or chemical synthesis procedures due to eco-friendliness, simplicity and low cost. Formation of silver nanoparticles was monitored at regular intervals using UV-Vis spectroscopy. Different phases and the crystal nature of silver nanoparticles were studied by X-ray diffraction (XRD). Transmission electron microscopy (TEM) was performed to realize the shape, size and morphology of the nanoparticles. Fourier transform infrared (FTIR) spectroscopy of the particles revealed the role of organic molecules that reduced and capped the colloidal particles in the medium during interaction. Most importantly, the rapid colorimetric sensing activity of these biosynthesized nanoparticles was explored and the green synthesized Ag nanoparticles instantly detected the presence of hazardous Hg2+ ions in water successfully.