Comparative evaluation of the efficiency of Endophytic Aspergillus and Penicillium spp. for gold nanoparticles biosynthesis

Abstract

Gold nanoparticles (AuNPs) are highly explored due to their interesting optical and physicochemical properties and biological synthesis is a cheaper and eco-friendly method to prepare AuNPs. In this study, the biosynthetic capacity of two fungal isolates Penicillium sp. (Eucalyptus leaves) and Aspergillus sp. (Capparis leaves) for the production of AuNP was compared. Visual color change, UV-Vis spectroscopy, particle size analysis based on microscopy and quantitative, transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FESEM) were used as a means of assessing the fungal filtrates. AuNP produced by Penicillium sp. had a reproducible surface plasmon resonance peak of 507.00 ± 0.50 nm, with a maximum absorbance of 0.823 ± 0.012 AU, while for Aspergillus sp., the surface plasmon resonance peak was 376.00 ± 0.50 nm, and the maximum absorbance was 0.244 ± 0.007 AU. The differences in both cases were highly significant (p<0.001), with the peak wavelength exhibiting a very large effect size (r = 0.99998) and the maximum absorbance having a very large effect size (r = 0.99971). The average particle size of 60 microscopy derived measurements was 33.53 ± 10.21 nm with a range between 15.65 and 57.27 nm, corresponding to a polydisperse population of nanoscale particles. The shape of the particles was spherical or quasi-spherical, mostly, and dispersion and localized aggregation were variable as observed by electron microscopy. The CVs across the three independent replicates of Penicillium sp were 0.10%, 1.47% and 1.20% for peak wavelength, maximum absorbance and mean particle size respectively, respectively indicating good experimental reproducibility. Penicillium sp. has been found to be more reproducible and prolific AuNP associated response than Aspergillus sp. under the tested conditions making it an eco friendly biological system for gold nanoparticle biosynthesis.

DOI: https://doi.org/10.54633/2333-025-059-013