In this study, the optical properties of glycated (HbA1c) and non-glycated (Hb) hemoglobin are compared using Surface-enhanced Raman spectroscopy (SERS), spectrofluorimetry, refractometry. Analysis spectral shift SERS spectra showed good discrimination between two hemoglobins indicating differences in their molecular structure. The fluorescence measured at excitation wavelengths 260, 270, 280 n...