Gamma radiation induced synthesis of gold nanoparticles in aqueous polyvinyl pyrrolidone solution and its application for hydrogen peroxide estimation

Gold nanoparticles (Au nps) have been synthesized in aqueous solution of polyvinyl pyrrolidone (PVP) by gamma radiolysis from HAuCl4 center dot 3H(2)O precursor and in presence of small concentrations of Ag+, 2-propanol and acetone. The effect of different experimental parameters, such as concentration of reactant, molecular weight of PVP on nanoparticle formation was studied. TEM image confirmed that spherical Au nps were formed when PVP of molecular weight 360,000 Da was used as capping agent H2O2 is a reactant in the enzyme catalyzed reaction of o-phenylene diamine (o-PDA). The reaction product has a weak absorption in the yellow region of the spectrum. When this product interacts with Au nps, it leads to enhancement of the absorption peak. The nanoparticles synthesized by radiation method were used for estimation of H2O2. The absorbance value of this peak at lambda(max) was observed to change with H2O2 concentration, which was monitored for estimation of H2O2. The response is linear in the range of 2.5 x 10(-6) mol dm(-3) to 2 x 10(-4) mol dm(-3) and 1 x 10(-7) mol dm(-3) to 3 x 10(-6) mol dm(-3) H2O2 in two separate sets of experimental parameters with detection limit 1 x 10(-7) mol dm(-3). (C) 2011 Elsevier Ltd. All rights reserved.