Biosynthesis of Silver Nano/Micro-Particles Using <i>Sambiloto</i> (<i>Andrographis paniculata</i>) Leaves Extract: Effect of AgNO<sub>3</sub> Solution Concentrations

Abstract

Silver nano/micro particles have been successfully produced via biosynthesis using sambiloto (Andrographis paniculata) leaves extract as the reductor agent. The obejctive of current was to study the effect of four different AgNO3 solution concentrations (i.e. 0.0125, 0.025, 0.05, 0.075 M) on the production of silver nano/micro particles via biosynthtesis. The sambiloto extract concentration used in this study was 0.5% w/v. The silver nano/micro particles produced via biosynthesis was characterized using UV-Vis spectrophotometer and Scanning Electron Microscopy (SEM). The UV-Vis analysis results showed that absorbance peaks for all four samples were observed at wavelength around 450 nm, which can be attributed to the presence silver nano/microparticles. The absorbance peak values for all samples were 0.1115; 0.0876; 0.052; 0.0424 for AgNO3 solution concentration of 0.0125; 0.025; 0.05; 0.075 M, respectively. The UV-Vis analysis results could also qualitatively conclude that the size of silver nano/micro particles produced at lower AgNO3 solution concentration were smaller than the size of silver nano/micro particles produced at higher AgNO3 solution concentration. In the other hand, SEM image showed that the size of silver particles prepared using AgNO3 solution concentration of 0.075 M was in the range of 5 – 10 μm, hence it can be called silver micro-particles. It was assumed that the size of silver nano/micro particles produced at higher AgNO3 solution concentration were bigger than the size of silver nano/micro particles produced at lower AgNO3 solution concentration.