Biosynthesis of silver-gold nanocomposites using Aspergillus fumigatus ND2 OR636497 and Aspergillus flavus ND1 OR636491 and evaluation of their biological activities


  • Dalia M. Abdelrahman
  • Nashwa Abdullah
  • Ehab B. Eldomany
  • Ahmed H. Moustafa
  • Mohamed E. Osman



Background: Recently, synthesis and use of innovative nanomaterials in food packaging industries has gained great interest not only in reducing the incidence of foodborne pathogens but also in preventing the changes of food ingredients that can be resulted from microbial growth and contamination. 

Objective: Our study concerned with the design of silver-gold bimetallic nanoparticles to provide an innovative strategy for improving the antibacterial activity of gold nanoparticles and reduce the toxicity of silver nanoparticles yielding a promising bimetallic nanocomposite for food packaging and biomedical applications. 

Methods: In the current study, metal-contaminated soil has been utilized in a trail to isolate new fungal isolates with good metal redox potential for metallic nanoparticles production. Size, shape, metal ratio, surface charge, nature of compounds involved in the formation and capping of the produced Ag-Au nanocomposites were estimated. Antimicrobial and cytotoxic behavior of these nanocomposites has been tested.

Results: New Aspergillus fumigatus and Aspergillus flavus isolates with good potential for Ag-Au bimetallic nanocomposite production have been isolated. The produced nanocomposites showed sphere-like polyhedron shape, 10-25 nm size range, and exhibited the truncated tetrahedron pattern as the most common topographical pattern.  Gold was the major metal in the nanocomposite synthesized by Aspergillus fumigatus ND2 OR636497 but Aspergillus flavus ND1 OR636491 nanocomposite showed a reversed case. Both nanocomposites recorded good surface charge value (-29.0 ± 2.3 & -27.3 ± 0.4) that can support a reasonable stability for the prepared nano solution. They exerted a good inhibitory effect against all tested Gram-negative and Gram-positive bacteria and showed significant antifungal behavior. In a trial to evaluate the safe applicability of the biosynthesized Ag-Au nanocomposites and to estimate their anticancer potential, their cytotoxic effect against a normal and cancer cell line has been evaluated. Results revealed their lower toxicity against the mice bone marrow cells and their elevated toxicity against MCF7 cell line with significant IC50 values.

Conclusion: This study provides efficient methods for green synthesis of Ag-Au nanocomposites utilizing new fungal isolates. Results revealed the safe and promising applicability of the biosynthesized Ag-Au nanocomposites in food packing as antimicrobial agent in addition to its promising anticancer activities.

Keywords: Aspergillus fumigatus, Aspergillus flavus, Ag-Au nanocomposite, antimicrobial, cytotoxicity, green synthesis.





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