The magnetic nanoferrites (Fe ₃ O ₄ , CoFe ₂ O ₄ , and NiFe ₂ O ₄ ) were synthesized via hydrothermal method using an aloe vera plant extract solution. Magnetic nanoferrites were characterized using X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), field emission electron microscope (FESEM), transmission electron microscopy (TEM), and X-ray photon spectroscopy (XPS). Cytotoxicity was obtained using the water-soluble tetrazolium salt (WST) assay. X-ray diffraction analysis also demonstrated that the size range of the nanoferrites exhibited average diameters of 6–28 nm and also exhibited high crystallinity. Results showed that all the metallic nanoparticles (NPs) are magnetic with saturation values of Fe = 52 emu/g, Co = 33 emu/g, and Ni = 20.43 emu/g. The magnetic nanoferrites exhibited a high cell viability rate at high concentrations and as shown from the optical images of the cells signifies their nontoxic and biocompatibility property. From SEM and TEM, the spherical structure was noticeable and the particle size is also in accordance with XRD. The chemical states for each NP also confirmed the successful synthesis of each nanoferrite. Not to mention, the heating capabilities of the nanoferrites were investigated and showed significant temperature increase of 6 °C–8 °C and acceptable specific absorption rate (SAR) values. Interestingly, the results assure that the materials would be suitable as magnetic mediators for magnetic hyperthermia application for cancer treatment.

Levitated systems in vacuum have many potential applications ranging from new types of inertial and magnetic sensors through to fundamental issues in quantum science, the generation of massive Schrödinger cats, and the connections between gravity and quantum physics. In this work, we demonstrate the passive, diamagnetic levitation of a centimeter-sized massive oscillator, which is fabricated using a method that ensures that the material, though highly diamagnetic, is an electrical insulator. Electrical conductors moving in a magnetic field experience eddy damping—which can severely reduce their motional quality factor. By chemically coating a powder of microscopic graphite beads with silica and embedding the coated powder in high-vacuum compatible wax, we form a centimeter-sized thin square plate which magnetically levitates over a checkerboard magnet array. The insulating coating reduces eddy damping by almost an order of magnitude compared to uncoated graphite with the same particle size. These plates exhibit a different equilibrium orientation from pyrolytic graphite due to their isotropic magnetic susceptibility. We measure the motional quality factor to be Q∼1.58×105 for an approximately centimeter-sized composite resonator with a mean particle size of 12 μm. Furthermore, we apply delayed feedback to cool the vertical motion of frequency ∼19 Hz and achieve center-of-mass temperature decrease by three orders of magnitude.

Since the publication of the 12 principles of green chemistry in 1998 by Paul Anastas and John Warner, the green synthesis of metal and metal oxide nanoparticles has emerged as an eco-friendly and sustainable alternative to conventional chemical methods. Plant-based synthesis utilizes natural extracts as reducing and stabilizing agents, minimizing harmful chemicals and toxic by-products. Ag nanoparticles (Ag-NPs) exhibit strong antibacterial activity; Au nanoparticles (Au-NPs) are seen as a promising carrier for drug delivery and diagnostics because of their easy functionalization and biocompatibility; and ZnO nanoparticles (ZnO-NPs), on the other hand, produce reactive oxygen species (ROS) that kill microorganisms effectively. These nanoparticles also demonstrate antioxidant properties by scavenging free radicals, reducing oxidative stress, and preventing degenerative diseases. Green syntheses based on plant extracts enhance biocompatibility and therapeutic efficacy, making them suitable for antimicrobial, anticancer, and antioxidant applications. Applying a similar “green synthesis” for advanced nanostructures like graphitic carbon nitride (GCN) is an environmentally friendly alternative to the traditional ways of doing things. GCN exhibits exceptional photocatalytic activity, pollutant degradation efficiency, and electronic properties, with applications in environmental remediation, energy storage, and biomedicine. This review highlights the potential of green-synthesized hybrid nanocomposites combining nanoparticles and GCN as sustainable solutions for biomedical and environmental challenges. The review also highlights the need for the creation of a database using a machine learning process that will enable providing a clear vision of all the progress accomplished till now and identify the most promising plant extracts that should be used for targeted applications.