Highly crosslinking core–shell magnetic nanocomposites based catalyst and heat free polymerization for isolation of glycoprotein

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2021-2022

The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates is a well-established technique and this review is the 12th update of the original article published in 1999 and brings coverage of the literature to the end of 2022. As with previous review, this review also includes a few papers that describe methods appropriate to analysis by MALDI, such as sample preparation, even though the ionization method is not MALDI. The review follows the same format as previous reviews. It is divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of computer software for structural identification. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other general areas such as medicine, industrial processes, natural products and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. MALDI is still an ideal technique for carbohydrate analysis, particularly in its ability to produce single ions from each analyte and advancements in the technique and range of applications show little sign of diminishing.

Polyhedral oligomeric silsesquioxane-modulated mesoporous amorphous bimetallic organic frameworks for the efficient isolation of immunoglobulin G

The efficient and accurate separation of immunoglobulin G (IgG) plays a vital role for disease diagnosis and therapy, but it is always hampered by the huge geometric size and complex structure of IgG. In this work, an amorphous Fe/Co bimetallic organic framework (denoted as PMOF-Fe/Co) is fabricated for IgG separation, with octa-carboxyl polyhedral oligomeric silsesquioxane (OCPOSS) as modulator for the first time. Benefiting from the rigid nanostructure and competitive coordination of OCPOSS, the aperture of PMOF-Fe/Co is enlarged to ∼20 nm along with the generation of enormous structural defects, which enables the accommodation of protein species with high molecular weights and large sizes. OCPOSS is also found exerting a positive impact on mediating the specific recognition and adsorption ability of PMOF-Fe/Co towards IgG through metal affinity, hydrophilic and hydrophobic interactions. Consequently, the multimode and multivalent affinity of PMOF-Fe/Co gives rise to an extraordinary adsorption capacity (2691.7 mg g-1) and satisfactory practical application performance. This study is convinced to provide a simple avenue for the efficient separation of specific large-sized proteins, as well as the engineering of abiotic affinity reagents with compositional and architectural complexity.

Metal-assisted core-shell plasmonic nanoparticles for small molecule biothiol analysis and enantioselective recognition

Cysteine (Cys) enantiomorphs, important small-molecule biothiols, participate in various antioxidative, flavoring, and poison-removing processes in the food industry. Current cysteine enantiomorph analysis methods require effective strategies for distinguishing them due to their similar structures and reactivity. Herein, we present a metal ion-assisted enantiomorph-selective surface-enhanced Raman scattering (SERS) biosensor based on an amphiphilic polymer matrix (APM), which can promote cysteine enantiomorph (L/D-Cys) identification. The highly selective molecular orientation is perhaps caused by the intermolecular hydrogen bonding with chiral isomers (metal centers). The experimental results show that the SERS biosensor has a sensitivity-distincting factor toward L-Cys and D-Cys. The linear range is from 1 mmol L-1 to 1 nmol L-1, along with a low limit of detection of 0.77 pmol L-1. Moreover, the fabricated Cu-APM biosensor exhibits remarkable stability and high repeatability, with an RSD of 3.7%. Real food cysteine enantiomorph detection was performed with L-Cys-containing samples of onion, cauliflower, garlic, and apple, and D-Cys-containing samples of vinegar, black garlic, cheese, and beer. The results show that the Cu-APM biosensor can be utilized as a powerful tool for real-time determination of Cys enantiomorphs in different food samples. Thus, the metal-ion-assisted enantiomorph-selective SERS biosensor has potential as an adaptable tool for enantiomorph detection and food sample analysis.

Virus-Like Magnetic Heterostructure: an Outstanding Metal-Complex Active Platform Enables High-Efficiency Separation and Catalysis

Assembled heterostructure systems, as emerging functional materials, have broad applications ranging from enzyme and drug payload to catalysis and purification. However, these require trial- and -error design process and complex experimental environment to generate heterostructure materials. Here, this study describes an easy-to-execute strategy to fabricate magnetic heterostructure as multifunctional delivery system. We utilize first-row transition metal copper and nitroso/amino ligand as modules to assemble around Fe3 O4 magnetic nanoparticles by excessed mild stimuli and fabricate the magnetic heterostructure materials (Fe3 O4 @ TACN NPs (tetraamminecopper (II) nitrate)). Notably, the Fe3 O4 @ TACN NPs present with cat's-whisker structure containing ligand and metal center. The nitroso-group ligands exhibit strong binding affinity to heme-structure enzyme, ensuring effective capture and isolate of cytochrome C (Cyt-c), resulting in their excellent isolation property. The copper complex-powered magnetic heterostructure materials can effectively isolation Cyt-c from complex biological sample (pork heart). Importantly, the Fe3 O4 @ TACN NPs coordinated with heme-structure, induced methionine 80 (Met80) disassociates from heme prosthetic group, and contributed to peroxidase-like (POD-like) activities increasing. These results exhibit that copper complex-powered magnetic heterostructure materials can not only satisfy the Cyt-c isolation and immobilization in an alkaline medium, but also be of the potential for improving the immobilization enzyme reactor performance.