Synthesis, characterization and vibrational spectroscopic studies of different particle size of gold nanoparticle capped with polyvinylpyrrolidone

Different sizes of gold nanoparticle (AuNPs) were prepared by UV irradiation technique. Polyvinylpyrrolidone (PVP) used as a stabilizing agent, and reducing agent was sodium borohydride. The main particle size was calculated from TEM images and the particle size was depending on the wavelength and time of UV irradiation. The FTIR data obtained that the band position of CO and C–N of pyrrolidone ring was shifted as a result of donor–acceptor interactions between these groups with AuNPs surface. The origin of the surface plasmon resonance (SPR) was explored from UV–VIS spectroscopy. The surface plasmon resonance (SPR) band position was explained in terms of the size of AuNPs. The results were confirmed that SP resonance was depending on the particle sizes that depend on the wavelength and time of UV irradiation.