Facile preparation of 3-D floor-like ordered mesoporous carbon functionalized graphene composites and its application for selective enrichment of N-glycans from human serum

Novel 3-D floor-like ordered mesoporous carbon functionalized graphene composites, FLOMC-GO, with high graphitized carbon contents were successfully synthesized using a soft template method. The one-pot sol-gel method was employed to prepare the silica soft template. Then, the sandwich-like composites were further combined together to form a 3-D structure through pre-carbonization and carbonization . During these procedures, the sulphonyl and sulfide bridges were formed by cross-linking processes to connect the phenyl rings. The prepared FLOMC-GO was confirmed to have a large pore volume (1.03   cm 3   g −1 ), high BET surface area (544.99   m 2   g −1 ) and well-ordered mesoporous structure with a narrow pore-size concentrated at 3.74   nm. The content of carbon reached 80% and was highly graphitized. By taking advantage of the interactions between carbon and glycans, FLOMC-GO was utilized to enrich N-linked glycans from OVA and human serum. As expected, excellent size-exclusion was found during the enrichment of N-glycans released from OVA, and 25 N-linked glycans were identified. The intensity of glycans enriched by FLOMC-GO was 7 times to the result of active carbon, while the ratio of OVA digestion to BSA interfering proteins increased to 1:50. Additionally, 31 N-linked glycans in total were enriched from human serum. The relatively easy synthesis as well as ability to enrich N-linked glycans with high selectivity and efficiency makes FLOMC-GO a promising adsorbent material for the discovery of human serum biomarkers for disease diagnosis.