Gold nanoparticle: synthesis and characterization

Aim: The aim of present study was to synthesize and characterize gold nanoparticles applicable in therapeutics and diagnostics tool for different diseases in particular for peste des petits ruminants (PPR). Materials and Methods: Gold nanoparticles were synthesized by the reduction of Au+3 (HAuCl) to Au-0. For this purpose, the reduction reaction between tetrachloroauric acid (HAuCl4) and trisodium citrate (Na3C6H5O.2H(2)O) was used in an aqueous solution. The initial gold concentration, trisodium citrate concentration and temperature were changed and their effects on particle size and size distribution were observed. At the end of the reduction reaction, gold nanoparticles with narrow size distribution were obtained. Zeta sizer and transmission electron microscopy (TEM) were used to characterize and determine the size and size distribution of the synthesized gold nanoparticles. Results: In the present work optimal gold salt concentration, trisodium citrate concentration and temperature were found to be 20 mM, 1.5% and 97 degrees C respectively. The morphology, size, and shape of synthesized gold nanoparticles were characterized by using spectrophotometry, transmission electron microscopy (TEM) and zeta sizer. In our study colloidal gold nanoparticle of 15-20 nm size were obtained. Conclusions: The uniform gold nanoparticles were synthesized by the citrate reduction method. The effects of various experimental parameters (Gold salt concentration, trisodium citrate concentration and mixing rate) on its size and size distribution at optimum pH and temperature were investigated. The gold nanoparticle synthesized by this method has been used for the preparation of gold-labeled lateral flow strip for peste des petits ruminants (PPR) diagnosis.