Preliminary Biological Evaluation of Powder-like Perovskite/Metal oxide Nanocomposite Developed by a Facile Wet-chemical Method

Abstract

In this study, CsPbBr₃ nano-powder was sonicated, and then an electrostatic self-assembly process was employed for coating it on TiO₂ to generate a perovskite/metal-oxide nanocomposite (NC). Electron microscopy (SEM) was used to analyze the perovskite nanoparticles’ structural and morphological features. This investigation confirmed successful NC synthesis, as particle sizes and morphologies were properly determined. Along with various materials-based characterizations, the biological effect of the corresponding nano-powders (i.e., CsPbBr₃, TiO₂, and their NC) was determined and discussed to reveal the initial biotechnological features, including but not limited to cell viability. Moreover, the interaction between the NC and Xanthomonas campestris-exposed tomato plants was analyzed, which reflected increased proline content, indicating a superior defense response in TiO₂/CsPbBr₃-treated plants against the aforementioned bacterium. CsPbBr₃ alone exhibited a lower proline level (1.51 mg g⁻¹ FW) in the corresponding plants compared to TiO₂ (2.23 mg g⁻¹ FW), while the TiO₂/CsPbBr₃ NC showed an intermediate effective value (1.91 mg g⁻¹ FW). Moreover, cell-viability results revealed the toxic nature of CsPbBr₃: from day 1 to day 3, cell viability decreased from 80% to 40%, which was mitigated when CsPbBr₃ was combined with TiO₂.