The Effect of Gold Salt Concentration in the Production of Gold Nanospheres

The optical, electrical and chemical properties of the gold nanospheres synthesized by different gold concentrations in deionized water through a simple chemical reduction method (Turkevich method) were studied.They were dependent on the variation of the gold salt concentration.The peaks of the surface Plasmon resonance (SPR) absorption band and their wavelengths were detected by a UV-visible spectrophotometer.The diameters of the spherical gold nanoparticles were measured theoretically using UV-visible absorption spectrum analysis of the synthesized gold nanoparticles in colloidal form by calculating the ratio of the absorbance at the surface Plasmon resonance (SPR) peak to the absorbance at the lowest peak closed to SPR peak.The values of the gold nanoparticles diameters were (23 nm) and decreased to (13 nm) as the function of molarity changed in the range (0.1 -0.3 mM).They were compared with the results of the transmission electron microscopy (TEM), which was about (15 -20 nm) measured by the reference images of Sigma-Aldrich values.The conductivity measurements showed increasing the conductivity with molarity increased.The total dissolved solids (TDS) exhibited increase by linear relation with molarity increasing.The pH-value of the gold nanoparticles solutions varied with the molarity and recorded a bowing value of pH-value at (0.2 mM).