Biosynthesis of silver nanoparticles using Sambiloto leaf extract: optimization process and characterization

It has been synthesized silver nanoparticles (AgNP) with biological method or biosynthesis, successfully. The synthesis is done using extract of Sambiloto leaf (Andrographis paniculata Ness). The study involved determining the optimum volume ratio of synthesis i.e. AgNO₃ solution: extract solution and characterization of nanoparticles formed. The concentration of AgNO₃ solution used was 1 M and extract solution was 7.5 g/L. The characterization included UV-Vis spectrophotometer, EDS, TEM, XRD and FT-IR spectrophotometer. The results obtained were, the optimum volume ratio of synthesis was 10 µL:10 ml. The characteristics of AgNP formed were the Surface Plasmon Resonance (SPR) absorbance at a wavelength of 423 nm. The diffraction peaks observed at angles 2θ of 38.18°, 45.81° and 64.87° which corresponded to the hkl (111), (200) and (220). These results showed that the crystal structure of AgNP formed was face center cubic (FCC) with lattice parameter a, of 4.03 Å. TEM characterization showed that the size of AgNP nanoparticles was about 10 - 30 nm. (author)