Biosynthesis and characterization of gold nanoparticles produced by laccase from Paraconiothyrium variabile

During recent years investigation on the development of eco-friendly processes for production of gold nanoparticles (GNPs) have received much attention due to hazardous effects of chemical compounds used for nanoparticle preparation. In the present study, the purified laccase from Paraconiothyrium variabile was applied for synthesis of Au nanoparticles (AuNPs) and the properties of produced nanoparticles were characterized. The UV–vis spectrum of formed AuNPs showed a peak at 530 nm related to surface plasmon absorbance of GNPs represented the formation of gold nanoparticles after 20 min incubation of HAuCl4 (0.6 mM) in the presence of 73 U laccase at 70 °C. Transmission electron microscopy (TEM) image of AuNPs showed well dispersed nanoparticles in the range of 71–266 nm as determined by the laser light scattering method. The pattern of energy dispersive X-ray (EDX) of the prepared GNPs confirmed the structure of gold nanocrystals.