A novel cationic covalent organic framework as adsorbent for simultaneous removal of methyl orange and hexavalent chromium.

The simultaneous removal of toxic, carcinogenic organic dyes and metal ions from water by one material offers significant advantages when fast, facile, and robust water purification is required. Ionic covalent organic frameworks (ICOFs) have the combined properties of COFs and ion exchange resins and are expected to achieve simultaneous capture of heavy metal ions and organic dyes from water. Herein, a novel guanidinium-based ICOF was synthesized using a solvothermal method. Benefitting from the cationic character, porosity and nanoscale pore size of ICOFs, the adsorbent exhibited high simultaneous adsorption capacities of 290 mg g-1 and 158 mg g-1 for methyl orange (MO) and Cr(vi), respectively, and retained more than 90% adsorption capacity after six adsorption-desorption cycles. In addition, based on dual control of size-exclusion and charge-selection, precisely selective adsorption is achieved towards diverse mixed anionic and cationic pollutants. This strategy offers a practical solution for COFs to confront environmental pollution issues.

A novel Wulff-type boronate acid-functionalized magnetic metal-organic framework imprinted polymer for specific recognition of glycoproteins under physiological pH.

Boronate affinity molecularly imprinted materials have been widely used for the separation of glycoproteins under alkaline conditions that is not conducive to the structural stability of the protein. In this work, a kind of novel molecularly imprinted polymer (MIP/TBA/MOF@Fe3 O4 ) was prepared via grafting self-assembled molecular team of boronic acids on the surface of the magnetic metal-organic framework core. The teamed boronate affinity was formed by 2-mercaptoethylamine and 4-mercaptophenylboronic acid for specific separation of glycoproteins under physiological pH (pH 7.4). The obtained nanoparticles show high binding capacities (337.8 mg/g), fast adsorption equilibrium time (20 min), and good specificity (imprinting factor, 4.52) for glycoproteins under physiological pH. Furthermore, the prepared imprinted polymer still shows good adsorption capacity for glycoprotein after five times of repeated use, and its adsorption capacity only dropped by 4.7%. More importantly, the prepared nanoparticles have good potential to adsorb glycoproteins from real biological samples.

Highly Efficient Separation of Glycoprotein by Dual-Functional Magnetic Metal-Organic Framework with Hydrophilicity and Boronic Acid Affinity.

Protein glycosylation plays a critical role in post-translational modifications of proteins in the organism and is involved in many diseases. However, the huge challenge for glycoproteins to be highly specific isolated and adsorbed from complicated biological samples results from their low abundance and interference. In this work, a novel dual-functionalized magnetic metal-organic frameworks nanoparticle for selective enrichment of glycoproteins was synthesized for the first time. Due to the abundant amino groups and grafted phenylboronic acid, the proposed nanoparticles have the dual properties of hydrophilicity and boronic acid affinity. The obtained nanoparticles show high binding capacities toward glycoproteins under physiological state (pH 7.4) such as ovalbumin (327.28 mg/g), transferrin (241.17 mg/g), horseradish peroxidase (530.79 mg/g). Furthermore, the nanoparticles still have excellent enrichment performance after being used six times repeatedly. More importantly, the prepared nanoparticles also have great potential applications in the adsorption of glycoproteins from complex biological specimens.

Rapid and efficient separation of glycoprotein using pH double-responsive imprinted magnetic microsphere.

As biomarkers of many diseases, glycoproteins are of great significance to clinical diagnostics. However, the determination of low abundant glycoproteins in complex biological samples without any pretreatment process is still a problem. In this study, a rapid and convenient separation method for highly efficient enrichment of glycoproteins is reported, based on pH double-responsive imprinted magnetic microspheres. Thin imprinted polymer shells were fabricated onto the surface of magnetic microspheres by free radical polymerization, using 2-(Dimethylamino) ethyl methacrylate as pH-sensitive monomer, 4-vinylphenylbronic acid as boronate affinity monomer, and ovalbumin (OVA) as template molecule. Combining the advantages of pH-sensitive monomer and boronate affinity monomer, rapidly capture-release of OVA could be modulated by changing solution pH. Moreover, high absorption ability (81.2mg/g) was achieved within about 10min. This study provided responsible way to imprint glycoproteins and showed great potential for glycoprotein detection in clinical diagnostic.