Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Halide and Thiocyanate Metal Acid Complexes Extraction in the Water – Ethoxylated Nonylphenol – Ammonium Sulfate System

Неионные оксиэтилированные ПАВ, в том числе оксиэтилированные нонилфенолы, могут рассматриваться как нейтральные кислородсодержащие экстракционные реагенты, образование расслаивающихся систем с которыми возможно при высаливании неорганическими солями. В работе исследовано распределение галогенидных и тиоцианатных ацидокомплексов таллия (III), железа (III), индия и галлия в системе вода – оксиэтилированный нонилфенол (неонол АФ 9-12) – сульфат аммония при 25 °C. Установлено, что количественно извлекается таллий в виде тетрагалогенидталлат-иона при кислотности более 0,1 моль/л, извлечение остальных металлов не количественное. Среди тиоцианатных ацидокомплексов количественно концентрируется цинк, кобальт и медь (II), что может использоваться для группового концентрирования указанных металлов или их экстракционно-спектрофотометрического определенияNonionic ethoxylated surfactants, including ethoxylated nonylphenols, can be considered as neutral oxygen-containing extraction reagents, the formation of delamination systems with which is possible when salting-out with inorganic salts. In this work, the distribution of halide and thiocyanate acid complexes of thallium (III), iron (III), indium and gallium in the water – ethoxylated nonylphenol (neonol AF 9-12) – ammonium sulfate system at 25°C was investigated. It is established that thallium (III) is quantitatively extracted in the form of tetrahalidetallate-ion with an acidity of more than 0.1 mol/l, extraction of other metals is not quantitative. Among the thiocyanate acid complexes, zinc, cobalt and copper (II) are quantitatively concentrated, which can be used for group concentration of these metals or their extraction-spectrophotometric determination method