The synthesis of lanthanum (La) substituted Zn (Mn0.6Zn0.2La0.2Fe2O4) and Fe (Mn0.6Zn0.4La0.2Fe1.8O4) was performed using sol-gel auto-combustion techniques to investigate the effects of lanthanum doping on the structural and magnetic properties of Mn-Zn nanoferrites. X-ray diffraction and transmission electron microscopy confirmed the development of a single-phase spinel structure and a reduction in crystallite size (from 16 to 10.7 nm) with La substitution. Although saturation magnetization (Ms) decreased due to changes in cation distribution and magnetic interactions, La doping led to an increase in initial permeability. This enhancement was linked to changes in Ms and the magneto-crystalline anisotropy constant (K1). The permeability loss factor (tan δµ) remained low (around 10- 2) for the La-doped ferrites, indicating minimal energy loss at room temperature. These results suggest promising potential for advanced biomedical applications, in line with Sustainable Development Goals (SDGs). The sol-gel auto-combustion technique provides a scalable and environmentally friendly method for synthesizing these materials, supporting SDG targets related to responsible consumption and production (SDG 12).
A novel surface plasmon resonance (SPR) biosensor design for point-of-care detection of different bacteria is presented. It consists of a SiO2 prism, metal (Ag), silicon carbide (SiC), 2D materials of zirconium nitride (ZrN), and a sensing medium. The proposed structure's angular reflectivity is investigated using the transfer matrix method (TMM) following optimization of the Ag and SiC layer thicknesses. For the various types of bacteria such as Staphylococcus (S) aureus, faecalis 9790, aureus Duncan, and aureus 52A5, the maximal sensitivity of 327, 362.45, 301.46, and 269.87°/RIU is achieved with remarkable minimum reflectance (Rmin). According to simulation results, using a new class of 2D materials significantly improves the sensor performance over the conventional SPR configuration. Furthermore, the proposed SPR structure is presented with COMSOL Multiphysics to measure the electric field enhancement factor and intensity close to the ZrN material-sensing layer interface. Using the fabrication technologies to fabricate the proposed sensor as an SPR chip is worthwhile due to its real-time and label-free detection of malaria diseases.