Biosynthesis and Antibacterial-Activity of Silver and Gold Nanoparticles Using Liquorice Root: A Green Chemistry Approach

Nanobiotechnology has gained a great impetus in modern world with potential application to human welfare. An important area of nanobiotechnology is the development of reliable and environmental friendly approach for synthesis of nanoscale particles through biological systems. This study primarily focuses on biosynthesis of gold and silver nanoparticles using extract of liquorice root employing green chemistry approach. The treatment of aqueous solution of AgNO3 and HAuCl4 with liquorice root extract resulted in rapid formation of stable nanoparticles of both the metals. The growth of nanoparticles is monitored by UV-visible spectrophotometer. The bio-nanoscale particles were further characterized using transmission electron microscopy, atomic absorption spectroscopy; X-ray diffraction and fourier transform infrared spectroscopy. Transmission electron microscopy revealed the presence of polydisperse gold and silver nanoparticles with an average size of 46.6 nm and 30.2 nm respectively. X-ray diffraction studies corroborated that the biosynthesized nanoparticles are crystalline gold and silver. Furthermore, liquorice root mediated gold and silver nanoparticles shows significant amount of antibacterial activity may be due to the phytochemicals absorbed on its surface and could act as an effective antibacterial agent offering sustainable alternative for the development of effective antibacterial agents to overcome the problem of resistance.