Novel Co3O4 Nanoparticles/Nitrogen-Doped Carbon Composites with Extraordinary Catalytic Activity for Oxygen Evolution Reaction (OER)

Abstract Herein, Co3O4 nanoparticles/nitrogen-doped carbon (Co3O4/NPC) composites with different structures were prepared via a facile method. Structure control was achieved by the rational morphology design of ZIF-67 precursors, which were then pyrolyzed in air to obtain Co3O4/NPC composites. When applied as catalysts for the oxygen evolution reaction (OER), the M-Co3O4/NPC composites derived from the flower-like ZIF-67 showed superior catalytic activities than those derived from the rhombic dodecahedron and hollow spherical ZIF-67. The former M-Co3O4/NPC composite displayed a small over-potential of 0.3 V, low onset potential of 1.41 V, small Tafel slope of 83 mV dec−1, and a desirable stability. (94.7% OER activity was retained after 10 h.) The excellent performance of the flower-like M-Co3O4/NPC composite in the OER was attributed to its favorable structure

Intact NIST Monoclonal Antibody Characterization - Proteoforms, Glycoforms - using CE-MS and CE-LIF

10.1080/23312009.2018.1480455Cogent Chemistry41148045

Intact NIST monoclonal antibody characterization—Proteoforms, glycoforms—Using CE-MS and CE-LIF

<p>Determining and linking the structural heterogeneity of recombinant antibodies to function is critical in the biopharmaceutical industry. We introduce a new microfluidic capillary electrophoresis—mass spectrometry (μCE-MS) approach to characterize intact monoclonal antibody (mAb) and simultaneously quantifying distinct variants. Our MS analysis of intact NIST mAb (RM8671) shows 18 variants identified amongst proteolytic and glycolytic modifications with a range of relative abundances between 0.1% and 100%. In order to verify our quantitative MS results, we used an established system based on capillary electrophoresis—with laser induced fluorescence (CE-LIF) for profiling the N-glycans. All major glycans were identified and further substantiated by exoglycosidase digestion. Interestingly, the µCE-MS analysis of intact NIST mAb consistently yielded higher amounts of G2FG2F-Hex glycoform (~3.4%), whereas the CE-LIF analysis indicates that only 1.4% of G2F-Gal is present. Therefore, the additional hexose adduct observed in µCE-MS may have been the glycation product of the mAb. Further analysis of deglycosylated mAb with µCE-MS made it possible to reveal the glycation with 10.5% of one hexose product and 4.9% of two hexose product in the intact deglycosylated antibody. An integrated solution using two orthogonal and complementary techniques for characterizing antibody glycosylation is provided here.</p