Kokum fruit mediated biogenic gold nanoparticles with photoluminescent, photocatalytic and antioxidant activities

Abstract

Abstract Biosynthesis of gold nanoparticles (AuNPs) is rapidly emerging area of research and development. In this study, simple, rapid and green method that uses Kokum fruit extract for synthesis of photoluminescent AuNPs with catalytic and antioxidant activities has been reported. For synthesis, the parameters such as 0.6 mM HAuCl4, 1:3 ratio of HAuCl4 to extract, pH 4 and incubation at 80 °C for 15 min were found optimum. The biogenic AuNPs were characterized by UV visible spectroscopy, fourier transform infra-red (FTIR) spectroscopy, energy dispersive X-ray (EDS) spectroscopy, X-ray powder diffraction (XRD) pattern analysis, selected area electron diffraction pattern (SAED) analysis and transmission electron microscope (TEM) imaging. The photoluminescence investigation showed broad excitation band with excitation maximum at 311 nm and emission band with an emission maximum at 455 nm. Noteworthy, the fluorescence emitted by AuNPs was found to be excitation dependent. The investigation of catalytic activity demonstrated that AuNPs possess good photocatalytic activity and could be used for rapid photocatalytic degradation of methylene violet (MV) dye. In addition, AuNPs showed good dose dependent DPPH radical scavenging activity. The proposed method demonstrated that Kokum fruit extract can be used for rapid and green synthesis of photoluminescent AuNPs with catalytic and antioxidant activities.