Multifunctional magnetic composite nanoparticles (NPs) with antibiotics have demonstrated symbiotic effects because of their promising antimicrobial properties. The antimicrobial agent reduces side effects and dosage, and increases drug delivery efficiency. In this study, SiO₂ coated over Fe₃O₄ magnetic nanoparticles (MNPs) were prepared by a solvothermal method. The MNPs were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), and Fourier transform infrared spectroscopy (FTIR). The antimicrobial tests were carried out using the disk diffusion method. The electrochemical sensing was investigated by cyclic voltammetry with varying As(III) concentrations from 1–10 ppb. The microstructural results showed the formation of spherical-shaped Fe₃O₄@SiO₂ MNPs with 15–30 nm diameters. UV-vis results showed that Fe₃O₄ NPs promote visible light absorption of Fe₃O₄@SiO₂ MNPs because of well-structured and unvarying shell thickness which is beneficial for the absorption of organic dyes. With an increase in the concentration of As(III), there was a shift in potential and an increase in oxidation peak current, showing the electrocatalytic capacity of the modified electrode. The SiO₂ deposited on Fe₃O₄ displayed an admirable microbial operation. These Fe₃O₄@SiO₂ MNPs are easily absorbed by cells and have the potential to influence bacterial cells both within and outside of the cell membrane, making them an intriguing candidate for use in a variety of biological applications in the future.

Reactive magnetron sputtering deposition of nickel oxide (NiO) films were done on p-type silicon substrate and glass substrate under Ar+O2 gas environment at substrate temperature of 26 °C, 100 °C, 200 °C and 300 °C. The phase, crystallinity and grain size were analysed by x-ray diffraction in grazing incidence mode (GIXRD). The average grain size varied in the range of 12 nm to 28 nm for NiO films. The microstructural analysis was carried out under a field emission scanning electron microscopy (FESEM) as well as transmission electron microscopy (TEM). Uniform distribution of grains and lower surface roughness were observed for the NiO films processed at relatively higher temperature. Direct band gap of investigated NiO films were measured with the help of absorption data obtained from UV-visible photospectrometer. The direct band gap was found to vary from ≈2.92 eV to ≈ 3.96 eV with change in substrate temperature.

In this study, the authors have designed biocompatible nano-vesicles using graphene oxide (GO) for the release of chlorambucil (CHL) drugs targeting cancerous cells. The GO sheets were first sulfonated and conjugated with folic acid (FA) molecules for controlled release and high loading efficiency of CHL. The chlorambucil (CHL) drug loading onto the functionalized GO surface was performed through π-π stacking and hydrophobic interactions with the aromatic planes of GO. The drug loading and “in vitro” release from the nano-vesicles at different pH were studied. The average particle size, absorption, and loading efficiency (%) of FA-conjugated GO sheets (CHL-GO) were observed to be 300 nm, 58%, and 77%, respectively. The drug release study at different pH (i.e., 7.4 and 5.5) showed a slight deceleration at pH 7.4 over pH 5.5. The amount of drug released was very small at pH 7.4 in the first hour which progressively increased to 24% after 8 h. The rate of drug release was faster at pH 5.5; initially, 16% to 27% in the first 3 h, and finally it reached 73% after 9 h. These observations indicate that the drug is released more rapidly at acidic pH with a larger amount of drug-loading ability. The rate of drug release from the CHL-loaded GO was 25% and 75% after 24 h. The biotoxicity study in terms of % cell viability of CHL-free and CHL-loaded GO against human cervical adenocarcinoma cell line was found to have lower cytotoxicity of CHL-loaded nano-vesicles (IC₅₀ = 18 μM) as compared to CHL-free (IC₅₀ = 8 μM). It is concluded that a high drug-loading efficiency and controlled release with excellent biotoxicity of CHL-GO offers an excellent application in the biomedical field.