The surface modification was performed as previously reported . In brief, nanopapers were cut into a 1 cm × 0.5 cm rectangular shape, and then immersed in 50 mM 1TBA or 0.1 mM for other boronic acids (BAs) in methanol for 1 hour. Before glycan measurement, the BA-coated nanopaper was air-dried. For the glycan measurement, the BA-coated nanopapers were spotted with the aqueous solutions containing glycans or glycoproteins in 100 mM MES buffer (pH 5) and incubated for 1 hour. Before Raman measurement, the paper was dried in an oven at 75℃ for 5 minutes.