An organic inorganic hybrid material based on nanocrystals of zeolite L functionalized with silicon phthalocyanine can develop interesting properties when activated by natural sunlight. Cell viability tests show that this nanomaterial is able to photoinactivate mouse cells and Escherichia coli (E. coli) bacteria, and is also very efficient against the self-defense mechanisms of E. coli during the first minutes of solar irradiation. The results suggest that Gram-negative E. coli become more resistant to singlet oxygen-based disinfection treatments at higher temperatures. The present work contributes to the development of new functional materials for a range of important sunlightbased applications. (C) 2015 Elsevier Ltd. All rights reserved.