Fig. 2. The linearity between the band area ratio and glucose concentration.

(A) Averaged spectra during each of the four clamping periods. The average glucose concentration for each clamping period is shown in the legend. The black arrows indicate the glucose Raman peak at 1125 cm⁻¹ and the protein/lipid peak at 1450 cm⁻¹. (B) Glucose concentration versus the band area ratio corresponding to the black arrows in (A). The solid line displays the result of linear fitting (R = 0.94). (C) Prospective prediction using the band area ratio in (B) (R = 0.94, MARD = 13.4%).