The current techniques for glycoprotein analysis require tedious sample preparation, including enzymatically releasing glycans from glycoproteins and chemically labeling glycans for detection . For example, the glycosidase (PNGase F/PNGase A) could be used to cleave the N-glycans from glycoproteins, and then the glycans are purified via hydrophilic interaction liquid chromatography (HILIC) . According to the detection techniques, chemical labeling of the glycans may be required for liquid chromatography (LC) or liquid chromatography-mass spectrometry (LC-MS) . For O-glycan analysis, the procedure can be more complicated due to the lack of enzymatic cleavage methods.