Samples were taken from a paper manuscript dating back to 1370 AD. Isolated fungi were cultivated from different parts of the manuscript as well as from the storage environment. Seven fungi species were identified, including Aspergillus terreus, A. niger, A. flavus, Penicillium chrysogenum, Trichoderma viride, A. tamarii, and Gliocladium fimbriatum. Zinc oxide nanoparticles at concentrations of 0.3%, 0.6%, and 0.9%, as well as silver nanoparticles at concentrations of 50, 30, and 20 parts per million (ppm), were used. The concentration of 0.9% of isopropyl alcohol in zinc oxide nanoparticles and a concentration of 50 ppm in silver nanoparticles showed an inhibition rate of 90% and reached 100% for A. niger. These concentrations were applied to infected samples, which were examined using scanning electron microscopy. The infected samples exhibited a high density of fungi, especially A. niger and A. terreus, with clear penetration of hyphae and microorganisms between the fibers. There was a general weakening in the mechanical properties of the paper, such as tensile strength and elongation.
The selected concentrations were applied to the paper surfaces, and the mechanical properties were studied. It was found that the treated samples with zinc oxide nanoparticles and silver nanoparticles showed increased tensile strength and elongation, along with some improvements in the properties of severely damaged samples, particularly those infected with A. niger and A. terreus.