Relationship of CaZn2(OH)6·2H2O nanoparticles synthesized by different methods with its antifungal activity

Recent research has increasingly focused on synthesizing nanoparticles (NPs) through various methods to determine how these processes influence their characteristics, and consequently, their biological activity. Calcium zinc hydroxide dihydrate (CaZn 2 (OH) 6 ·2H 2 O) nanoparticles, designates as CZ, were obtained via sol–gel (CZ-SG), hydrothermal (CZ-HT), and microwave (CZ-MW) methods, and their properties were characterized using XRD, SEM, TEM, and BET analyses. The different synthesis revealed distinct CZ nanoparticle attributes, including variations in crystallite sizes (72 nm for CZ-SG, 65 nm for CZ-HT and CZ-MW) and morphologies (fibrous for CZ-HT and spherical agglomerates for CZ-SG and CZ-MW). Surface area analysis showed low values across all synthesis methods, with CZ-HT exhibiting the best surface area (8.154 m 2 /g). The investigation also explored how these synthesis routes influence antifungal efficacy against fourteen fungal strains associated with the biodeterioration of limestone cultural heritage structures. Our results highlight the notable antifungal activity of CZ-NPs, particularly those synthesized via the CZ-HT method, which demonstrated the most effective antifungal action as evidenced by the lowest minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). This effectiveness is attributed to the unique fibrous morphology, which proves to be highly inhibitory to fungal cell proliferation. These findings not only advance our understanding of CZ NPs-mediated antifungal mechanisms but also open a new effort for the development of effective preservation strategies for cultural heritage conservation.