N. Amin

Cobalt ferrite (CoFe₂O₄) nanoparticles (NPs) have become one of the most extensively studied spinel ferrites due to their remarkable physicochemical characteristics, such as high magneto crystalline anisotropy, excellent coercivity, notable chemical stability, adjustable optical band gap (1.3–1.9 eV), and significant saturation magnetization (50-80 emu/g). These inherent properties, further improved through cationic substitution and the formation of nanocomposites, make CoFe₂O₄ NPs highly adaptable for a wide range of technological uses. This review offers a thorough and up-to-date examination of the synthesis, structural characteristics, effects of elemental substitution, and various applications of CoFe₂O₄ NPs and their nanocomposites (NCs). The primary synthesis methods such as co-precipitation, sol-gel auto combustion, microemulsion, solvothermal, hydrothermal, and ceramic techniques are thoroughly assessed regarding control over particle size, level of crystallinity, and scalability. The effect of replacing main group elements, first and second transition series metals, and lanthanides on the structural, magnetic, electrical, and catalytic characteristics of CoFe₂O₄ is examined in detail. Various characterization techniques including XRD, FTIR, SEM/TEM, VSM, BET, and XPS are described to clarify the relationships between structure and properties. The applications assessed include environmental remediation techniques, biomedical applications, and energy storage solutions. The review highlights that strategic design of nanocomposites and precise substitution are essential methods for tackling the inherent drawbacks of unmodified CoFe₂O₄ and realizing its complete multifunctional capabilities.

The current study is based on Zn/ZnO nanoparticles photodynamic therapy (PDT) mediated effects on healthy liver cells and cancerous cells. The synthesis of Zn/ZnO nanoparticles was accomplished using chemical and hydrothermal methods. The characterization of the synthesized nanoparticles was carried out using manifold techniques (e.g., transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS)). In order to study the biotoxicity of the grown nanoparticles, they were applied individually and in conjunction with the third generation photosensitiser Fotolon (Chlorine e6) in the in vivo model of the normal liver of the Wister rat, and in the in vitro cancerous liver (HepG2) model both in the dark and under a variety of laser exposures (630 nm, Ultraviolet (UV) light). The localization of ZnO nanoparticles was observed by applying fluorescence spectroscopy on a 1 cm² selected area of normal liver, whereas the in vitro cytotoxicity and reactive oxygen species (ROS) detection were carried out by calculating the loss in the cell viability of the hepatocellular model by applying a neutral red assay (NRA). Furthermore, a statistical analysis is carried out and it is ensured that the p value is less than 0.05. Thus, the current study has highlighted the potential for applying Zn/ZnO nanoparticles in photodynamic therapy that would lead to wider medical applications to improve the efficiency of cancer treatment and its biological aspect study.