Magnetic and hydrophilic imprinted particles via ATRP at room temperature for selective separation of sulfamethazine

Preparation of Magnetic Surface-Imprinted Polymer Microspheres with Hydrophilic External Layers for Selective Extraction of Fluoroquinolones from Eggs

A novel method of one-pot covalently grafting a hydrophilic organic polymer imprinted layer on the surface of magnetic microspheres was developed for the preparation of restricted access materials–molecularly imprinted magnetic microspheres (RAM-MIMMs) with water compatibility and ability to exclude biomacromolecules and selectively enrich analytes. The magnetic nanoparticles were coated with silica gel, modified with vinyl groups, polymerized with the template (enrofloxacin), functional monomer (glycidyl methacrylate, methacrylic acid), and cross-linking agent (ethylene glycol dimethacrylate) in chloroform, and then the hydrophilic surface was formed by a ring-opening reaction. The RAM-MIMMs were characterized by transmission electron microscopy, FT-IR spectroscopy, and adsorption experiments and demonstrated average diameters around 400 nm and a coating thickness in the range of 50 nm. They exhibited high selectivity of the imprinted cavities and hydrophilicity of the external surface with water compatibility and exclusion of biomacromolecules. The RAM-MIMMs were used for the magnetic dispersion microextraction of fluoroquinolones from egg samples with satisfactory results.

Designed synthesis and surface engineering strategies of magnetic iron oxide nanoparticles for biomedical applications

Iron oxide nanoparticles (NPs) hold great promise for future biomedical applications because of their magnetic properties as well as other intrinsic properties such as low toxicity, colloidal stability, and surface engineering capability. Numerous related studies on iron oxide NPs have been conducted. Recent progress in nanochemistry has enabled fine control over the size, crystallinity, uniformity, and surface properties of iron oxide NPs. This review examines various synthetic approaches and surface engineering strategies for preparing naked and functional iron oxide NPs with different physicochemical properties. Growing interest in designed and surface-engineered iron oxide NPs with multifunctionalities was explored in in vitro/in vivo biomedical applications, focusing on their combined roles in bioseparation, as a biosensor, targeted-drug delivery, MR contrast agents, and magnetic fluid hyperthermia. This review outlines the limitations of extant surface engineering strategies and several developing strategies that may overcome these limitations. This study also details the promising future directions of this active research field.