Synthesis of gold nanoparticles and study their effect on optical properties of acridine orange dye

Abstract

In this work, a fluorinated Acridine Orange dye dissolved in distillate water at four
different molar concentrations (0.5 ×10-6, 1 × 10-6,0.5 × 10-5, and 1 × 10-5). Gold
nanoparticles were prepared using the chemical reduction method using gold
chloride at a concentration of (0.01 M) with sodium citrate. The reaction resulted in
a red liquid containing gold nanoparticles. Using a particle size analyzer device, an
analysis was carried out for the red liquid containing gold nanoparticles and the
proportion of 45% of the liquid contained particles of (9-11 nm) size. The gold
nanoparticles were added to the prepared dye samples with different volume
concentrations (5,10, and 15) % for each prepared sample. The linear optical
properties of the prepared samples before and after the addition were studied using a
spectrophotometer within the range (200-800 nm). The optical parameters of all
prepared samples were calculated (absorbance, transmittance, reflectivity,
absorption coefficient, linear refractive index, extinction coefficient, optical
conductivity), and the results showed the presence of a wide peak of absorption and
an increase in the value of the optical parameters after adding gold nanoparticles
and their increase with increasing the concentration of nanoparticles as well as
movement of absorption peak towards longer wavelengths (red shift).