Synthesis of gelatin stabilized gold nanoparticles with seed particles enlargement by gamma Co-60 irradiation

Gold nanoparticles (AuNPs) with size from 13 to about 36 nm were synthesized by γ-irradiation method using gelatin as a stabilizer. The AuNPs with controllable size were prepared using various concentrations of Au³⁺ from 0.5 to 2 mM and seed particle enlargement with different ratios of [Au³⁺]/[Au^o] up to 50. Maximum absorption wavelength (λ_max) was measured by UV-Vis spectroscopy, and particle size was determined from TEM images. Results showed that the size of AuNPs was affected by the Au³⁺ concentration. The seed enlargement approach is efficient to control the size of AuNPs. The value of λ_max shifted from 527.5 nm (seed particles) to 537.5 nm, and the size of AuNPs increased from 13 nm (seed particles) to 36 nm for concentration ratio of [Au³⁺]/[Au^o] up to 40. Thus, γ-irradiation method is favorable for production of AuNPs with controllable size and high purity. The AuNPs/gelatin synthesized by γ-irradiation with the advantages of environmental friendly and mass production process may be potentially promising for applications in medicines, cosmetics and in other fields as well. (author)