The interest that awakens the ZnO as material is greatly extended both by its unique properties as by its wide variety of applications. Within these applications, antimicrobial activity is gaining relevance. Especially, the bactericidal activity of ZnO nanoparticles is outstanding but little is known about antifungal activity. In addition, the recent discussion about the potential toxicity of nanoparticles and their massive use places them in the spotlight. In response to this emerging problem, a simple and general approach to synthesize hierarchical structure of ZnO is reported. A formation mechanism of these surprising structures is proposed. Moreover, the obtained zinc oxide hierarchical particles improves the antifungal activity towards Aspergillus niger in contrast to ZnO micro or nanoparticles. Due to surprising results, the different action mechanisms of ZnO hierarchical particles against fungi are studied. Thus, we pose a novel physical mechanism by which ZnO hierarchical particles achieve excellent fungicidal results.

This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under projects MAT2013-48009-C4-1-P. The Spanish National Research Council (CSIC) under project NANOMIND CSIC 201560E068. Dr. F. Rubio-Marcos is also indebted to MINECO for a “Juan de la Cierva” contract (ref: JCI-2012-14521), which is co-financedwith FEDER funds F. R-Mis also indebted toMINECO for a ‘Ramon y Cajal’ contract (ref: RyC-2015-18626),which is co-financed by the European Social Fund. Finally, the authors are grateful to Mercedes Monte-Serrano, Santiago De-Bernardi and Javier Menéndez for antimicrobial activity test.

Peer Reviewed