Mycosynthesis of gold nanoparticles using the extract of Flammulina velutipes, Physalacriaceae, and their efficacy for decolorization of methylene blue

This study is the first report on the usage of fresh fruiting bodies of Enoki mushroom (Flammulina velutipes) as a new green reducer agent incorporated in the mycosynthesis of gold nanoparticles. The mycosynthesized AuNP was characterized for its physical and chemical properties using optical observation, UV–vis spectrometer, FESEM, AFM, DLS, XRD, Zeta Potential, and FTIR analyses. The optimized AuNPs were then tested for its efficacy in the decolorization of Methylene Blue (MB). The purple color of AuNPs indicates that the solution contains a mixture of triangular, spherical, and irregular shapes with an average of size 74.32 nm. The pattern of XRD clearly showed that the formed AuNPs were crystalline while DLS and Zeta Potential data showed that mycosynthesized AuNPs exhibited good stability and aggregation properties in colloidal form. FTIR showed the attachments of polysaccharides, amino acids and phenol as reducer agents on AuNPs. The efficacy test exhibited that the degradation of MB increased with the increase of the incubation time in presence of AuNPs. The proof-of-concept that mycosynthesized AuNPs by fungal natural organic materials of Flammulina velutipes can act as catalysts in reducing the MB dye is proven by the best decolorization of MB at 75.35 % after 4 h soak.