The growth of a wide variety of microorganisms on stone substrates is considered one of the main degradation processes of stone heritage. These microbial agents can deteriorate stone, generating acidolytic and oxido-reductive corrosion in stone minerals. In this context, metal nanoparticles might be an effective tool for controlling the biodeterioration because present great advantages (high surface to volume ratio and small particle size). Among all of them, magnesium and zinc oxides are particularly interesting as low cost and environmental friendly materials, with interesting antimicrobial activity without the presence of light. In this way, in order to obtain nanoparticles with high antifungal activity, controlled MgO, ZnO and Zn-doped MgO (Mg1−xZnxO) nanoparticles (NPs) were synthesized via sol-gel method. The nanoparticles were firstly studied by Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and X-rays Diffraction (XRD), and then the antifungal activity of the single and Zn-doped magnesium oxide nanoparticles were studied against Aspergillus niger (TM3H174) and Penicilium oxalicum (TM3H776), which are especially active in deterioration of stone heritage. The experimental results showed the successful use of the sol-gel synthesis route to obtain crystalline MgO, ZnO and Zn-doped MgO nanostructures with potential properties for the conservation of the stone heritage. The MgO and Zn-doped MgO nanoparticles displayed the best antifungal activity against A. niger and P. oxalicum fungus. The successful antifungal properties observed suggest the utilization of prepared nanoparticles as a potential novel antifungal agent in stone-built cultural heritage.

Trabajo presentado en el 5th YOuth in COnservation of CUltural Heritage, celebrado en Madrid (España) del 21 al 23 de septiembre de 2016

Research funded by Geomaterials 2 (S2013/MIT_2914) Programme.

Peer reviewed