Facile preparation of a novel chitosan-derived porous graphitized carbon biomaterial for highly efficient capture of N -glycans.

The comprehensive characterization of N -glycans is of significant importance for the discovery of potential biomarkers and the diagnosis and therapy of diseases. Herein, we designed and fabricated a porous graphitized carbon biomaterial (CS-900-1C) using cheap and available chitosan as the carbon source via a facile pyrolysis process and a post-oxidation strategy for the effective capture of N -glycans. Thanks to its large surface area (2846 m 2 g -1 ), high graphitization degree, suitable oxidation degree and unique porous structure, the CS-900-1C biomaterial exhibits an ultralow detection limit (1 ng μL -1 ), an excellent size-exclusion effect (OVA digest : BSA protein : OVA protein, 1 : 1000 : 1000, w/w/w) and satisfactory reusability (at least 8 cycles) in the capture of standard N -glycans. Moreover, CS-900-1C has successfully been applied in profiling the difference of N -glycans during diabetes progression (obesity, impaired glucose tolerance, diabetes patients and healthy control) where we discovered that the expression levels of five N -glycans show a gradually increasing trend as diabetes progresses. Remarkably, the five specific N -glycans could be considered as biomarkers to accurately diagnose the progression of diabetes. Our work not only developed a novel porous graphitized carbon biomaterial for the large-scale characterization of N -glycans but also provided new guidance for the precise therapy of diabetes.