A novel and green adsorbent based on sulfobetaine-modified magnetic Fe₃O₄ nanoparticles (SBMNPs) was successfully synthesized via a convenient one-step chemical coprecipitation method and applied to the removal of the anionic dyes methyl blue (MB) and amaranth (AM) from aqueous solution. The morphology and properties of the SBMNPs were characterized using various methods, including Fourier-transform infrared spectroscopy, X-ray powder diffraction, transmission electron microscopy, and vibrating-sample magnetometry. The obtained SBMNPs were easily dispersible in water and exhibited excellent superparamagnetic behavior. For the adsorption process, four experimental parameters, namely, the solution pH, initial dye concentration, reaction time, and adsorbent dosage, were optimized. The adsorption process was remarkably fast and reached equilibrium within 15 min. The isotherm data were consistent with the Langmuir model, and the maximum adsorption capacities of the SBMNPs were 127.06 mg·g⁻¹ and 57.01 mg·g⁻¹ for MB and AM, respectively, which exceed those reported for other adsorbents. The adsorption kinetics were well fitted by a pseudo-second-order model, which indicated chemical adsorption. Furthermore, the SBMNPs displayed good recyclability, removing 80.92% of MB and 77.49% of AM in the fifth cycle. Owing to their rapid adsorption properties and facile synthesis from green and inexpensive starting materials, the SBMNPs may represent a promising new adsorbent for the removal of anionic dyes from aqueous solution.

In this study, glutathione (GSH)-responsive magnetic mesoporous silica nanoparticles grafted by disulfide organosilicon (SMNPs) were synthesized, characterized, and evaluated as controlled drug carriers. The nanoparticles exhibited consistent dispersion, considerable drug-loading capacity, and high saturation magnetization. Importantly, they demonstrated the ability to release doxorubicin (DOX) by up to 43% in a reducing tumor microenvironment, highlighting their potential for targeted therapy. In addition, the SMNPs displayed favorable biocompatibility, making them suitable for biomedical applications. Most notably, the SMNPs loaded with DOX effectively killed both HepG2 and HeLa cancer cells, while also showing efficient cellular uptake in HeLa cells. These findings suggest that SMNPs are a promising platform for magnetic-targeted and GSH-responsive delivery of therapeutic agents.